Microbiology Immunology PhD Program - ETH ZPsr (LCP) homologues, MsrR, SA0908 and SA2103. Mutational studies revealed that LCP proteins are essential for optimal cell division and

4th Student Retreat

Microbiology amp Immunology PhD Program

Grand Hocirctel Chandolin 4th ndash 6th September 2011

H ig h e r Q u a lity B e tte r R e s u lts

special thanks to our sponsors

Dear Students

We would like to welcome you to the 2011 PhD student retreat of the MIM PhD Program at the wonderful Grand Hotel in the canton Valais

During these 3 days we will spend time to discuss research projects presented via oral presentations and poster sessions Moreover we are happy to announce that we have organized four guest speakers We chose representatives from the research areas of Immunology Microbiology and Forensic science In addition to the scientific talks we will have one speaker talking about how to successfully achieve your goals

Apart from the scientific part we have planned a BBQ a party and a short hiking trip for students to get to know each other In particular for students who have just started their PhDs this will be a great opportunity to get to know your fellow PhD students and make your start easier

We are looking forward to meeting all of you and would like to thank you for participating in this yearrsquos meeting We wish you a great time with all your fellow students and hope that you can enjoy the few days without working at the bench

Best wishes

The 2011 Organizing Committee

Le Grand Hocirctel Chandolin Valais

Contact information

Accommodation in Chandolin

Le Grand-Hocirctel Chandolin

Maison de Groupes Gruppenhaus CH-3961 Chandolin Tel +41 (0) 274 753 502 Fax +41 (0) 274 753 503 Web wwwlegrandhotelchandolinch

Organizing Committee

Josh Crouse +41 78 7250838

Andreacute Gladiator +41 78 6464156

Deepa Mohanan +41 79 6493507

Heike Nowag +41 78 6273403

Kathrin Schneider +41 76 7352007

Kerstin Weidner +41 76 5207121

Program MIM Retreat 2011

Sunday

1200 ndash 1300 arrival amp check in 1300 ndash 1430 lunch break 1430 ndash 1500 student session 1 (2 students) 1500 ndash 1600 guest speaker Dietmar Zehn 1600 ndash 1630 coffee break 1630 ndash 1730 student session 2 (4 students) 1730 ndash 1830 guest speaker Naseem Malik 1900 ndash 2030 dinner 2030 ndash 2200 poster session 1

Monday

0700 ndash 0830 breakfast 0900 ndash 1000 student session 3 (4 students) 1000 ndash 1030 coffee break 1030 ndash 1200 student session 4 (4 students) 1200 ndash 1300 guest speaker Damaris Wyss 1300 ndash 1430 lunch break 1430 ndash 1500 student session 5 (2 students) 1500 ndash 1600 guest speaker Martin Ackermann 1600 ndash 1630 coffee break 1630 ndash 1730 student session 6 (4 students) 1730 ndash 1900 poster session 2 1900 - hellip grill party

Tuesday

700 ndash 830 breakfast 900 ndash 1300 hiking 1400 departure

A special welcome to our Guest Speakers

Dietmar Zehn

Swiss Vaccine Research Institute University of Lausanne

Naseem Malik

Institute of Forensic Medicine University of Bern

Damaris Wyss

Work-with-joy Consulting + Coaching Zurich

Martin Ackermann

Molecular Microbial Evolution ETH Zurich

Speaker Dietmar Zehn

Assistant Professor

Swiss Vaccine Research Institute Department of Immunology and Allergology at the Centre Hospitalier Universitaire Vaudois Lausanne Switzerland

CV Dietmar Zehn studied medicine at Chariteacute the medical school of Humboldt University in Berlin Germany where he obtained the title Dr med in 2004 for his work on the kinetics of the presentation of MHC class-I restricted T cell epitopes In 2004 he joined the lab of Prof Michael J Bevan at the Howard Hughes Medical Institute at the University of Washington in Seattle as a senior research fellow where he investigated how the affinity of T cell receptors for self- and foreign-peptide MHC complexes impacts T cell responses In 2009 Dietmar joined the Swiss Vaccine Research Institute at the University of Lausanne In 2010 he was appointed as assistant professor at the Department of Immunology and Allergology at the Centre Hospitalier Universitaire Vaudois and University of Lausanne where he is currently working on basic and translational research in molecular and cellular immunology applied to immune self-tolerance and infectious diseases

Title Context-specific affinity thresholds for CD8 T cell activation

Abstract A fundamental requirement of the immune system is to be tolerant to self-antigens while being fully reactive to foreign-antigens Only then can we avoid destructive autoimmune reactions while maintaining robust responses to pathogens The ability of the immune system to eliminate T-lymphocytes directed against self-antigens is crucial for managing this task Several lines of evidence however indicate that not all auto-reactive T cells are eliminated While T-lymphocytes responding strongly to self-antigens are efficiently eliminated the immune system appears to routinely fail to eliminate cells that are weakly reactive with self-antigens These weakly self-reactive T-lymphocytes seem normally not to pose problems but under certain circumstances they may be activated and cause autoimmunity This can for instance happen during an infection with a pathogen that carries an antigenic motif which is similar to or mimics a self-antigen According to this notion T-cells with the potential to harm ourselves are found in all healthy individuals Following up on these observations we have developed a new transgenic mouse model in which we can study the potential of these T cells to cause autoimmunity and the mechanisms that prevent these cells from causing disease in healthy individuals

Speaker Naseem Malik MSc FAMH Abteilungsleiter Forensische Molekularbiologie Institut fuumlr Rechtsmedizin Bern CV Born and raised in Hong Kong then went to London England for further studies in

Medical Laboratory Sciences Came to Switzerland in 1981 and worked in the Department of Genetics at the University Childrenrsquos Hospital in Basel Returned to England in 1986 and obtained a Masters in Biochemistry Molecular genetics at the University of Sussex Returned as Head of the Laboratory of Molecular genetics at the Childrenrsquos Hospital Basel Became Head of the Department of Forensic Molecular Biology at the University Institute of Forensic Medicine Bern in 2000

Title Forensic application of DNA-Analysis Abstract The analysis of DNA for forensic purposes in Switzerland dates back to 1989

when DNA-Fingerprinting was first applied Since the initial limited utilisation a veritable explosion in applications has taken place fuelled by the development of the Polymerase Chain Reaction The Institute of Legal Medicine have been among the leaders pioneering techniques for the analysis of DNA from Cigarette-Butts and Bone The Swiss national DNA-Database was established in 2000 and has since proved to be indispensible for the justice system With the help of some chosen cases the successes and limitations of these applications will be illustrated

Speaker Lic phil Damaris E Wyss Owner of Wyss Consulting + Coaching Work with joy and success Neunbrunnenstrasse 212 8046 Zuerich CV D Wyss worked for 12 years in various corporations as an employee

then she decided to change her career and studied psychology (motivational psychology) educational psychology and employment law at the University of Zurich After her mastersrsquo degree she went to Munich to study coaching at the handow company Now she works as a certified coach and consultant building her own company with the idea to contribute to a fulfilling work life and success at the workplace As a coach she is interested in enhancing self-regulation in her clients and coaching people to reach their goals She consults mainly on 4 subjects Work motivation successpeak performance innovation mindset and learning in corporations

Title How to successfully achieve your goals Abstract Success is what many people would like to achieve Goals play a big

role in being successful This speech is focused on the practical side of achieving goals Based on science success literature and her own experience as a coach and consultant the following questions and how-torsquos are explored What is success Why are goals so important for your success How to set goals to be successful how to achieve those goals and how to get yourself to actually do the work Practical tools are explained and the main goal of the speech is to enable you to put your ideas into goal-focused action

Speaker Prof Dr Martin Ackermann

Molecular Microbial Evolution

ETHEawag

CV Martin Ackermann has a joint appointment at ETH Zurich and Eawag the Swiss

Federal Institute of Aquatic Science and Technology He did his PhD on bacterial

aging at the University of Basel and then worked for two years as a postdoc at

UC San Diego He joined ETH Zurich in 2004 and became professor for

Molecular Microbial Ecology in 2008

Title An evolutionary perspective on bacterial individuality

Abstract The focus of his research group is on basic questions on bacterial ecology and

evolution on the biological significance of phenotypic heterogeneity in clonal

populations on interactions within and between species and on how bacteria

cope with ever-changing environments The goal is to work on basic principles

with model systems in the laboratory and then to test these principles in more

natural situations The group often works at the level of single cells and asks

how this perspective provides insights that could not be obtained by populations

experiments One of the current specific interests is on how stochastic gene

expression can promote the emergence of different phenotypes in clonal

populations and in how these different phenotypes interact with each other

Abstracts of Oral Presentations

Talk No Name

1 Vanina Dengler 2 Mai Matsushita 3 Eva Baumlr 4 Walther Haumlnseler 5 Kamile Grabliauskaite 6 Fabio Serventi 7 Sonia Bastidas 8 Gustavo Gers-Huber 9 Stephan Schwager 10 Nadine Schmid 11 Aline Taveira 12 Nicolas Ponroy 13 Sanja Mandaric 14 Jonas Muumlller 15 Qian Chai 16 David Aebischer 17 Willem van de Veen 18 Jovana Cupovic 19 Kerstin Wanke 20 Isaak Quast

Student Session 1 Presentation 1 - 2

Student Session 4 Presentation 11 ndash 14

Deletion of LytR-CpsA-Psr Proteins in Staphylococcus aureus Activates the Cell Wall

Stress Response

V Dengler P Stutzmann Meier R Heusser S Burger Staufer B Berger-Baumlchi and N

McCallum

University of Zurich Institute of Medical Microbiology Gloriastr 32 8006 Zurich Switzerland

vdenglerimmuzhch

Staphylococcus aureus is responsible for a large proportion of nosocomial and community-

acquired infections worldwide and it is able to rapidly adapt to varying environmental

conditions and to develop resistance to virtually all antibiotics

The Staphylococcus aureus cell wall stress stimulon (CWSS) provides an intrinsic first line

of protection against a wide range of cell envelope-damaging agents CWSS induction is

mediated by the VraSR two-component system in response to an unknown signal triggered

by cell envelope damage or the inhibition of cell wall synthesis While some CWSS genes

are directly involved in cell envelope biosynthesis the roles and functions of many other are

unknown or poorly characterized The latter group includes all three S aureus LytR-CpsA-

Psr (LCP) homologues MsrR SA0908 and SA2103

Mutational studies revealed that LCP proteins are essential for optimal cell division and

influence cell envelope related phenotypes such as beta-lactam resistance autolysis biofilm

formation and virulence Introduction of CWSS reporter gene fusions into single double and

triple LCP mutants showed that deletion of these proteins activated CWSS gene expression

to varying degrees in the absence of external stress Basal levels of CWSS gene expression

in these mutants were up to 50-fold higher than in the wild type strain Inactivation of VraR in

the LCP mutants reduced CWSS expression back to wild type levels which indicated that

cell envelope damage or disturbances to cell wall synthesis caused by LCP protein deletion

activated VraSR signal transduction These results highlight the importance of LCP proteins

in cell envelope maintenance as similar increases in basal CWSS expression had previously

been linked to point mutations in the vraSR operon or the depletion of essential cell wall

synthesis enzymes including PBP2 MurA MurB and MurF

The Role of Glutathione Peroxidase 4 in the Immune System

Mai Matsushita Peter Bretscher Stefan Freigang Georg Bornkamm Marcus Conrad Manfred Kopf Molecular Biomedicine Institute of Integrative Biology ETH Zurich Schlieren Switzerland maimatsushitaenvethzch The selenoenzyme glutathione peroxidase 4 (Gpx4) is regarded as a major scavenger of phospholipid hydroperoxides and thus represents a key component of the reactive oxygen species (ROS) scavenging network While recent studies have characterized the potential functions of Gpx4 the underlying molecular mechanisms remain undefined In our studies we focus on the role of Gpx4 in the immune response against bacterial viral and parasitic pathogens Since the systemic Gpx4-deficiency results in embryonic lethality we have generated mice lacking Gpx4 selectively in T cells dendritic cells and macrophages by crossing mice with a floxed Gpx4 gene to the respective CD4-CD11c- and LysM-Cre transgenics Results from CD4cre-Gpx4loxlox mice revealed that despite normal thymic T cell development the peripheral T cell numbers were reduced in both spleen and lymph nodes Moreover CD4cre-Gpx4loxlox failed to mount efficient antiviral CD8+ T cell responses upon infection with LCMV or Influenza virus and showed delayed viral clearance Interestingly although both CD4+ and CD8+ T cells exhibited a highly reduced viability in vitro the infection-triggered T cell death was very pronounced among CD8+ T cells whereas the CD4+ T cell population appeared much less affected However the impaired virus-specific CD8+ T cell response was rescued upon diet supplementation with high concentrations of the antioxidant Vitamin E thereby indicating the increased toxicity of accumulating phospholipid hydroperoxides as a mechanism Since ROS are a causative factor in many degenerative disorders understanding the physiologic relevance and mechanism of action of Gpx4 may help to unravel the complex signaling network of redox regulation in the immune system

CALBICANS DERIVED T CELL EPITOPES AND THEIR PROTECTIVE CAPACITY IN MOUSE AND MAN

Eva Baumlr1 Andreacute Gladiator1 Sonia Bastidas Patino1 Bernd Roschitzki2 Salomeacute LeibundGut-Landmann1

1 ETHZ Institute of Microbiology 2 UZH ETH Functional Genomics Center Zuumlrich evabaermicrobiolethzch

Candida albicans is a dimorphic fungus which is normally found as harmless commensal in the human gastrointestinal and reproductive mucosa and can be isolated from the oral cavity of up to 80 of healthy individual However in immunocompromised settings Calbicans is a significant human pathogen that can lead to mucocutaneous or disseminated candidiasis Protection from these fungal diseases is dependent on both the innate and adaptive branch of the immune system There is strong evidence that T helper (TH) cells especially those of the TH17 lineage play a pivotal role in combating fungal infections as demonstrated by the increased prevalence of mycoses in AIDS patients However the fungal antigen to which the T cells are reactive and the mechanisms by which they confer protection remain unknown Here we have addressed the antigen-specificity By using an immunoproteomic approach we have identified seven potential Calbicans-derived T cell epitopes One of the candidates restimulates up to 20 of all TH17-cells activated during Calbicans infection and is able to prime TH cells which react strongly to Calbicans Furthermore we could show that it also serves as an epitope for human memory CD4 T cells and that these cells produce IL2 and IL17 but no IFN-gamma which is in line with the protective role of IL-17 that has been suggested from studies in mouse and man We are now addressing the protective capacity of TH cells specific for this epitope Together the data obtained from this research shall provide important new insights into the pathogenicity of Calbicans and the mechanisms of the host mediated immune response to this infection

Development of next generation gene therapy vector for p47phox-deficient form of chronic granulomatous disease (CGD) W Haumlnseler V Wohlgensinger M Bianchi A Thrasher M Grez RA Seger J Reichenbach U Siler University Childrens Hospital Zuumlrich Div of Immunology Steinwiesster 75 8032 Zuumlrich waltherhaenselerkispiuzhch CGD comprises a group of primary immunodeficiencies with X-linked gp91phox-deficiency (X-CGD) and p47phox-deficiency representing 70 and 20 of all cases Currently bone marrow (BM) transplantation is the only curative treatment option for about 50 of the patients with an available HLA-matching donor We develop gene therapy (GT) for p47phox-deficient CGD patients without an available BM donor as alternative treatment option In our recent clinical X-CGD GT trial we used an LTR driven gammaretroviral vector The trial was clinically successful as preexisting treatment-refractory infections were resolved However long term follow up revealed transactivation in haematopoietic stemprogenitor cells (HSCs) and transgene silencing as adverse events Therefore we are developing a next generation GT vector for the p47phox-deficient CGD under consideration of the risks of transactivation and silencing We circumvented transactivation in HSCs by the use of a retroviral self-inactivating (SIN) GT vector in combination with a myelospecific internal promoter driving p47phox expression This restricted p47phox transgene expression and thereby transactivation potential to terminally differentiated phagocytes in vivo in a p47phox-- mouse model To test for silencing we used the P19 cell line The SFFV promoterenhancer which was used and silenced in our X-CGD clinical trial was silenced in these cells within three weeks Silencing was inhibited by incorporation of deletion-constructs of the ubiquitous chromatin opening element (UCOE) 5rsquo to the SFFV promoter in our vector The new vector will be a lentiviral SIN vector with the myelospecific internal promoter driving p47phox expression which is protected from silencing by our UCOE deletion construct

Inflammation amplifies the regenerative response to pancreatic tissue loss Grabliauskaite K Sonda S Bain M Reding T Graf R Department of Visceral amp Transplantation Surgery University Hospital Zurich Raumlmistrasse 100 8091 Zuumlrich kamilegrabliauskaiteuszch Introduction Regeneration of the pancreas after pancreatitis or partial resection is very limited and volume increase of the organ has not been reported Nevertheless histological markers of cell cycle activation have been observed following tissue damage Objective The aim of this ongoing study is to evaluate in models of pancreatic injury (acute and chronic pancreatitis) and major tissue loss (60 pancreatectomy) the potential for regeneration Methods Acute and chronic pancreatitis were induced in mice by multiple injections of cerulein 60 pancreatectomy was achieved by resection of the pancreatic tail The expression of regeneration markers cell cycle regulators growth factors and tissue inflammation were analyzed by immunohistochemistry and qRT-PCR Results Proliferating pancreatic cells were observed following both cerulein treatment and 60 pancreatectomy Double staining with amylase and Ki67 indicated that proliferation was mainly confined to acinar cells confirming their proliferating potential However qualitative assessment of the remnant pancreas indicated that there was no volume growth suggesting that the cell cycle was activated but not completed To further investigate whether inflammation could enhance the pancreatic regenerative capability inflammation was induced by cerulein injections following resection In comparison to the single treatments the combined pancreatic injury resulted in a strongly accelerated proliferative response In addition the cell cycle inhibitors p27 and p21 were differentially regulated in the combined injury model Conclusions Inflammation combined with tissue loss accelerates cell cycle activation in the pancreas The role of cell cycle inhibitors in hampering completion of mitosis and volume regeneration is currently investigated using knocked out animals

Copper trafficking in Bradyrhizobium japonicum Characterization of putative copper chaperones Fabio Serventi Zeb Youard Doris Buumlhler Hauke Hennecke ETH Zuumlrich Institute of Microbiology Wolfgang-Pauli-Str 10 8093 Zuumlrich fabioserventimicrobiolethzch

Bradyrhizobium japonicum is a soil Gram negative bacterium able to live in free-living oxic and anoxic conditions or as N2-fixing endosymbiont in soybean root nodules This versatility is due to its branched respiratory chain The main aerobic terminal oxidase is a mitochondria-like aa3-type cytochrome c oxidase while the main symbiotic one is a cbb3-type oxidase Both terminal oxidases depend on copper for their functionality

We previously investigated the biogenesis of the aa3-type cytochrome c oxidase with regards to copper insertion TlpA and ScoI are involved in the CuA center biogenesis CoxG is required for the CuB center formation (Capitani et al 2001 Buumlhler et al 2010)

The bll4882-4878 operon is induced in Cu starvation conditions The predicted gene products suggest a role in Cu import into the periplasm and in its eventual trafficking to other targets Deletion of the operon causes a severe defect in cytochrome aa3 formation - restored by external Cu supply - and partial defects in other Cu-dependent processes The same cytochrome aa3 defect is observed in a bll4880 gene deletion mutant Biochemistry on its product is currently carried on so far proving the Cu(I)-binding ability of this putative Cu chaperone

We hypothesize that Bll4880 cooperates with ScoI and TlpA for the copper insertion in the CuA center of the cytochrome aa3 while the other gene products of the bll4882-4878 operon are involved in copper uptake and delivering to diverse targets This research might lead to the first description of a bacterial Cu uptake and trafficking system

THE IMPACT OF HIV-1 REPLICATION ON THE ACTIVATION OF CD8+ T CELLS WITH

SPECIFICITIES FOR DIFFERENT ANTIGENS

Sonia Bastidas Patino Huldrych Guenthard and Annette Oxenius

Institute for Microbiology Zuumlrich ETH Zuumlrich

soniabastidasmicrobiolethzch

Continuous loss of CD4+ T lymphocytes and systemic immune activation are

hallmarks of chronic HIV-1 infection Chronic immune activation is characterized by an

elevated expression of activation markers on T cells It is suggested that activation

induced cell death of these abnormally activated cells is one of the main causes of T-cell

decline Interestingly T cells with an activated phenotype are not necessarily HIV-specific

or HIV-infected Usually 1-2 of all circulating CD8+ T cells during chronic infection are

HIV specific whereas the level of CD8+ T cells exhibiting activated phenotypes is in the

range of 60 indicating that immune activation is not restricted to HIV-specific CD8+ T

cells It is believed that most of these cells are activated by nonspecific mechanisms

including cross-reactivity and cytokine-driven activation a phenomenon referred to as

bystander activation The mechanisms underlying this phenomenon are not well defined

Additionally little to nothing is known about the antigen-specificity of bystander activated

CD4+ and CD8+ T-cells

Pre-existing data of our group indicate that cessation of antiretroviral therapy (ART)

specifically leads to activation of CD4+ T cells with specificities for persistent Herpes virus

antigens in the absence of detectable reactivation of these members of the Herpes virus

family In this study we expanded our analysis to another cohort of patients to investigate

whether these observations also apply for CD8+ T cell responses specific for persistent

viral antigens during viral rebound Based on our preliminary data we propose that this

HIV-driven activation also occurs for CD8+ T cells specific for persistent antigens which

likely represent a large part of activated CD8+ T cells in untreated HIV infection and

thereby significantly contribute to chronic immune activation

APOBEC3 restriction of HIV Vif mutants in a humanized mouse model

Gustavo Gers-Huber1 Annette Audigeacute1 Marc Nischang1 Li Duo1 Mary-Aude Rochat1 Viviana Simon2 Roberto F Speck1

1Division of Infectious Diseases and Hospital Epidemiology University Hospital of Zurich University of Zurich Switzerland 2 Departments of Microbiology and Medicine The Global Health and Emerging Pathogens Institute Mount Sinai School of Medicine New York US

If left unchecked one or more of the seven cellular APOBEC3 DNARNA editing- enzymes deaminate the genome of retroviruses during reverse transcription reducing viral infectivity HIV-1 neutralizes some but not all APOBEC3 by Vif-mediated proteasomal degradation Partially active Vif alleles are found in patients suggesting that complete APOBEC3 neutralization is not necessary for viral replication We hypothesize that suboptimal Vif activity is essential for HIV-1 diversification and potentially the main driver of the HIV pandemic Here we examined the replication of wild-type (WT) and Vif-mutant viruses in humanized mice (immunodeficient mice transplanted with human CD34+ cells) We choose two Vif-mutant viruses that selectively fail to neutralize APOBEC3G or APOBEC3F Viral loads and CD4CD8 ratios were measured over time WT virus replicated and caused a profound decrease of CD4 T-cells over time In contrast one of the Vif mutants resulted in comparable replication but less strongly reduced the CD4CD8 ratio The last Vif mutant replicated poorly in most mice All viruses replicated well in the PBMCs of the same donors the CD34+ cells of which were used to complement the mice especially the Vif mutant that failed to efficiently spread in vivo In conclusion there is a striking difference between in vitro and in vivo replication of Vif mutants We speculate that this is due to compartmentalization or different APOBEC3 expression patterns in vivo Further experiments are ongoing to identify one or more APOBEC3 essential for restricting HIV spread and to examine the viral diversity associated with this phenotype in vivo

IDENTIFICATION OF BURKHOLDERIA CENOCEPACIA H111 VIRULENCE FACTORS BY USING MULTIPLE INFECTION HOSTS

Stephan Schwager1 Anugraha Mathew1 Aurelien Carlier1 Pamela A Sokol2 and Leo Eberl1

1 Department of Microbiology Institute of Plant Biology University of Zuumlrich Zuumlrich Switzerland 2 Department of Microbiology and Infectious Diseases University of Calgary Calgary Alberta Canada Contact Stephan Schwager sschwagbotinstuzhch Species of the Burkholderia cepacia complex (Bcc) can cause disease in plants and can

establish opportunistic infections in animals and in humans affected by immunodeficiency

chronic granulomatous disease or cystic fibrosis However virulence mechanisms are poorly

understood

Recent studies have demonstrated that non-mammalian infection models are higly valuable in

the identification of virulance factors In the case of Bcc strains infection models using

Caenorhabditis elegans Galleria mellonella and Drosophila melanogaster have been described

In this study approximately 6000 mutants from a B cenocepacia H111 random mini-Tn5

insertion library were screened by using the C elegans pathogenicity model Around 25 mutants

were found to be attenuated in this infection model To our surprise none of the mutated genes

coded for the biosynthesis of classical virulence factors like proteases or siderophores Instead

we found several mutants with deletions in metabolic and regulatory pathways The attenuated

mutants were tested with the D melanogaster pricking assay representing an acute infection

model To exclude host-specific factors all mutants which showed an attenuation in both of the

models were also tested using the G mellonella infection assay

We found that several mutants which were strongly attenuated in the C elegans model were

also less virulent in the D melanogaster pricking model Mutants strongly attenuated in the G

mellonella model were generally also attenuated in the D melanogaster pricking model

Factors linking quorum sensing and biofilm formation in Burkholderia cenocepacia H111

Nadine Schmid1 Silja Inhuumllsen1 Claudio Aguilar1 Angela Suppiger1 Kathrin Riedel2 and Leo Eberl1 1Department of Microbiology Institute of Plant Biology University of Zurich Switzerland 2Department of Microbial Proteomics Institute of Microbiology TU Braunschweig Germany These authors contributed equally to this work nschmidaccessuzhch Burkholderia cenocepacia H111 a CF isolate employs the CepIR quorum-sensing (QS) system to control the expression of virulence factors as well as the formation of biofilms To date however very little is known about the factors that link QS and biofilm formation In this study we have used a combined transcriptomic and proteomic approach to precisely define the QS regulon in B cenocepacia H111 Among the QS-regulated loci we focused on three gene clusters with potential impact on biofilm formation i) the bclACB lectin operon ii) a gene cluster coding for a fimA homologue and a putative chaperonusher pathway and iii) a locus comprising the large surface protein BapA and an ABC transporter By means of transcriptional fusions of the respective promoters to lacZ we could confirm the QS-dependent expression of all the three loci Analyses of defined mutants revealed that the type 1 pilus showed little if any effect on biofilm formation in both a static microtiter-dish based assay as well as in flow-through cells Inactivation of the bclACB lectins resulted in equal amount of biomass compared to the wild-type strain in the static biofilm assay but revealed characteristic hollow microcolonies when biofilms were cultured in flow-chambers suggesting that the lectins are important for the structural development of a biofilm Inactivation of bapA leads to a significant decrease of biofilm formation in both assays indicating that BapA plays a major role in biofilm formation on abiotic surfaces

HCMV uses distinct mechanisms to enter human and porcine endothelial cells

Taveira A Ponroy N Mueller NJ Millard AL Contributed equally

Division of Infectious Diseases and Hospital Epidemiology University Hospital of Zurich Switzerland

AlineTaveirauszch

Reactivation of HCMV is a potential risk of allo- and xenotransplantation We demonstrated that HCMV replicates in porcine cells in vitro Here we compared the mechanisms used by HCMV to enter human and porcine endothelial cells (hEC and pEC respectively)

Susceptibility of EC from different anatomical origins to an endotheliotropic (TB40E) and a fibrotropic (TB40F) HCMV strain was evaluated Involvement of receptor-mediated endocytosis was investigated by comparing the expression profile of HCMV entry receptors and by using various specific inhibitors of endocytosis

TB40E similarly infected both hEC and pEC as assessed by immediate early (IE) expression In contrast TB40F failed to infect hEC but rapidly translocated to the nucleus and efficiently initiated its replication in pEC To determine whether these differences were due to distinct entry mechanisms the relative involvement of receptor-mediated endocytosis was evaluated

We demonstrated that all four cell types displayed high levels of 1 integrins and intermediate

levels of PDGFR while EGFR was only expressed on microvascular pEC Interestingly

siRNA experiments revealed that PDGFR is not involved in HCMV entry into pEC Cells were finally treated with specific inhibitors of clathrin-mediated or caveolar endocytosis All drugs inhibited TB40E entry into hEC and pEC However inhibitors had no effect on TB40F entry into pEC suggesting that TB40F enters pEC in an endocytosis-independent manner

These findings suggest that the differential susceptibility of hEC and pEC to HCMV infection might be due to distinct entry pathways utilized by HCMV to enter cells from its own or from another species

Title Statin anti-cytomegalovirus activity and potentiation of ganciclovir anti-viral activity Abstract Statins have been demonstrated to have antiviral activities against HIV-1 HCV or poliovirus Here we investigated whether statins interfere with HCMV replication and may potentiate the antiviral activity of ganciclovir (GCV) Human endothelial cells (hEC) were treated with atorva- fluva- prava- or simvastatin at 3 doses a non toxic dose (NT) and two doses (IC20 IC50) inhibiting 20 and 50 of cell proliferation respectively IC50 doses had no effect on MxA expression or on the cell surface expression of HCMV entry receptors IC20 doses did not affect immediate early and early antigen expression but strongly inhibited late antigen expression All IC20 doses reduced HCMV infectivity by about 1 log In addition IC50 doses of atorva- prava- and simvastatin reduced HCMV titres by at least 15 log When EC were co-treated with the IC50 doses and mevalonate or cholesterol cholesterol failed to reverse the inhibitory activity of statins on HCMV titres whereas mevalonate completely abolished the effects of all statins but fluvastatin Finally whereas low dose of GCV alone reduced HCMV infectivity by 1 log co-treatment with the IC20 dose of pravastatin resulted in an additive effect leading to a 25 log reduction of the titre Additionally co-treatment of GCV with the IC20 dose of simvastatin reduced HCMV titre by almost 3 log indicating a synergistic activity of the drugs These findings demonstrate that statins exhibit a potent cholesterol-independent antiviral activity against HCMV acting via a different mode of action compared to GCV This may provide new opportunities for antiviral therapy Ponroy N Taveira A Mueller NJ Millard AL Contributed equally Division of Infectious Diseases and Hospital Epidemiology University Hospital Zuumlrich Switzerland

Altering the virus-host balance- on the role of IL10 in acute MCMV infection

Mandaric S Walton S Oxenius A

Institute for Microbiology ETH Zurich

sanjamandaricmicrobiolethzch

IL-10 is anti-inflammatory cytokine that plays an important role in the regulation of host

immunity to infection In order to dampen T cell mediated immunity to virus infection IL-10

exert pleiotropic suppressive effects to different cell types This suppression results in

reduction of harmful tissue damage for the host but often in an increased pathogen burden

since the capacity of innate immune system to instruct a proper adaptive response is

reduced under anti-inflammatory conditions For these reasons chronic viruses often exploit

IL-10 pathway in order to modulate virus-host balance towards their own benefit Indeed

prolonged virus persistence during chronic infections has been connected with the secretion

of IL-10 Here we sought to define early events during a course of cytomegalovirus infection

that could explain the impact on adaptive cell response observed thereafter We dissect that

IL-10 specifically limits MCMV-specific CD4 T cell responses by suppressing myeloid

dendritic cells and we identify NK cells to play a crucial role in NKDC crosstalk to promote

the induction of CD4 T cell protective immunity in the absence of IL-10 Taken together our

data show that induction of IL-10 during CMV infection alters the virus-host balance by

targeting NK cells and antigen presenting cells which results in poor priming of virus-specific

CD4 T cells thereby prolonging lytic CMV replication and altering severity of disease

Engineering methylotrophy

Jonas Muumlller Eva Potthoff Patrick Kiefer Julia Vorholt

Institute of Microbiology ETH Zurich Switzerland

Jonasmuellermicrobiolethzch

Methylotrophic bacteria utilize methanol and other reduced C1 compounds as their sole carbon and energy source For this purpose they evolved a number of specialized enzymes and pathways Independently of the concrete methylotrophic metabolism the first steps of carbon conversion are conserved Methanol is initially oxidized to formaldehyde which is subsequently used to produce energy and biomass This study aims at inserting genes encoding methylotrophy enzymes into a non-methylotroph to create an artificial methylotroph which can be used for conversion of methanol into value-added products

Establishment of a CCL19CCL21 dual transgenic system for investigating the functions of T cell zone stromal cells

Qian Chai1 Lucas Onder1 Thomas Ruumllicke2 Elke Scandella1 and Burkhard Ludewig1

1Institute of Immunobiology Kantonal Hospital St Gallen St Gallen Switzerland 2Institute of

Laboratory Animal Sciences Veterinary University Vienna Austria

Email address Qianchaikssgch

Many viruses such as the human immunodeficiency virus or measles virus replicate in stromal

cells resulting in destruction of secondary lymphoid organ (SLO) structure and in functional

impairment Stromal cells in lymph nodes (LN) and spleen organize the microenvironment of

lymphoid organs through production of cytokines and chemokines CC-chemokine receptor 7

(CCR7) ligands ELC (CCL19) and SLC (CCL21) are among the chemokines which are

expressed by FRCs the T cell zone stromal cells FRCs thereby critically regulates the

migration of CCR7 expressing lymphocytes and dendritic cells However only few studies have

assessed the molecular basis of this cell-cell-interaction in vivo mainly because suitable models

with stromal cell-specific gene expression have not been available In order to investigate the

functions of T cell zone stromal cells in vivo in more detail a novel bacterial artificial

chromosome (BAC) transgenic mouse model has been generated The constitutively active

promoter of ELCCCL19 was used to drive expression of the Cre and the reporter gene hCD4

In addition the SLC promoter was used to express the reporter gene hCD8 Three founder lines

of the transgenic mice have been obtained and crossed with Rosa26 EYFP mice for initial

transgene expression analysis Two of the three founder lines showed FRC-specific transgene

expression in LNs and spleen Taken together ELC-Cre mice enable in vivo targeting of T cell

zone stromal cells for future studies on FRC biology In particular this novel model will be

utilized to characterize the role of T cell zone stromal cells during viral infections

Assessment of the functionality of lymphatic vessels during acute and chronic inflammation David Aebischer Tamara Roumlthlin Reto Huggenberger Michael Detmar Cornelia Halin Institute of Pharmaceutical Sciences Swiss Federal Institute of Technology (ETH) Zurich Wolfgang-Pauli Str10 8093 Zurich Switzerland The lymphatic network undergoes several changes during inflammation Upon acute inflammation lymphatic vessels expand and upregulate adhesion molecules and chemokines thereby enhancing dendritic cell (DC) migration and the subsequent induction of adaptive immunity During chronic inflammation lymphatic endothelial cells additionally proliferate leading to both an increase in lymphatic vessels area and number To date the functionality of such a remodeled and expanded lymphatic network in terms of fluid drainage DC migration and overall induction of adaptive immunity remains largely unclear To address these questions we have made use of a recently described mouse model of psoriasis namely hemizygous VEGF-A transgenic mice in which murine VEGF-A164 is constitutively expressed in the epidermis under the control of the keratinocyte-specific keratin 14 promoter Unlike wild-type mice hemizygous VEGF-A transgenic mice are unable to down-regulate inflammation induced by a contact hypersensitivity response in the ear skin and develop chronic psoriasis-like inflammatory skin lesions Performing whole mount immunofluorescence we could show that lymphatic vessels are enlarged during acute inflammation and further enlarged during chronic inflammation in the ear We also observed that the lymphatic drainage is reduced during acute inflammation but restored and even increased during chronic inflammation Furthermore FITC-painting experiments revealed that DC migration to draining LNs was more enhanced during chronic inflammation as compared to the acute or uninflamed state Interestingly DCs present in the chronically inflamed ears of mice displayed a less mature phenotype as compared to DCs in acutely inflamed tissue Collectively these data suggest that the lymphatic vessels draining a chronically inflamed site are functional Furthermore the differences observed in DC migration fluid drainage and DC maturation suggest that the induction of adaptive immunity could be altered during chronic inflammation We are currently assessing the effect of lymphatic vessels remodeling during acute and chronic inflammation on T cell activation and T helper differentiation

Human Regulatory B cells in Allergic Disease W van de Veen B Stanic G Yaman S Soumlllner B Ruumlckert D Akdis C Akdis and M Akdis

Swiss Institute of Allergy and Asthma Research (SIAF) University of Zuumlrich Oberestrasse 22 7270 Davos Platz Switzerland willemvandeveensiafuzhch B cells are emerging as important regulators of immune responses Regulatory B cells expressing IL-10 suppress immune responses and the lack or loss of regulatory B cells leads to exacerbated symptoms in several autoimmune mouse models Another B cell-related immune regulatory response restricted to humans is induction of non-inflammatory IgG4 antibodies which is characteristic for all high dose antigen tolerance models We hypothesize that if a B cell plays an anti-inflammatory role the antibody isotype produced by the plasma cell originating from this B cell should be anti-inflammatory Therefore we want to characterize human IL-10-producing B cells and determine whether these cells differentiate into IgG4-secreting plasma cells IL-10-producing B cells were purified and microarray analysis was performed Several molecules including CD25 and PD-L1 were upregulated in IL-10-producing B cells IL-10-producing B cells suppressed antigen-specific T cell proliferation TLR9 stimulation of B cells induced production of IgG4 and this effect was strongly enhanced when cultures were supplemented with IL-10 Isolation of IL-10-producing B cells showed that these cells produce significantly higher levels of IgG4 than IL-10-negative cells Furthermore we used beekeepers as a human in vivo model to study regulation of IgG4 production Because of their profession beekeepers are exposed to high doses of been-venom and develop T and B cell tolerance towards bee-venom antigens B cells specific for the major bee venom allergen phospholipase-A2 showed increased IL-10 and IgG4 levels Taken together these data demonstrate that human suppressive B cells exist that produce mainly IgG4 after differentiation into plasma cells

Title Generation of MHV A59-specific TCR retrogenic mice

Jovana Cupovic Veronika Nindl Lilian Staerck Wolfgang Uckert Volker Thiel Burkhard Ludewig ETH Zuumlrich Institute of Immunobiology Kantonal Hospital St Gallen Rorschacherstrasse 95 CH-9007 St Gallen e-mail jovanacupovickssgch A vast number of viruses infect the human CNS many of them with devastating acute pathologies whereas others establish persistence resulting in chronic demyelinating (multiple sclerosis-like) disease Molecularly well-defined model infections can contribute to better understand the basic mechanisms underlying both acute virus-induced CNS pathologies and those factors that determine chronic disease The mouse hepatitis virus (MHV) belongs to the coronavirus family and is a natural mouse pathogen able to establish infection in both liver and CNS Since CD8+ T cells are key players in the control of MHV infection the aim of this project is to generate T cell receptor (TCR) retrogenic mice to better understand activation and differentiation pathways of MHV-specific CD8+ T cells To characterize TCRs of interest T cell hybridomas recognizing the immunodominant s598 epitope of the MHV A59 strain were generated Overall 5 clones expressing the TCR of interest were selected for further analysis After thorough characterization on the cDNA level TCRα and TCRβ chains were incorporated into a retroviral vector Those vectors enabled us to transfect RAG1-- stem cells and subsequently transfer them to irradiated recipient RAG1-- mice Such reconstituted retrogenic mice expressed MHV s598-specific TCRs on CD8+ T cells and can hence serve as T cell donors in adoptive transfer experiments First characterization of MHV specific retrogenic cells showed that the cells are functional and able to proliferate in vitro when incubated with peptide-loaded APCs Adoptive transfer of retrogenic cells into wild type mice revealed their in vivo

functionality in terms of protection from MHV-mediated liver pathology Our future experiments using retrogenic cells as a tool will focus on the role of antiviral CD8+ T cell responses in CNS inflammation

Control of Bronchial Epithelium Integrity and Tight Junctions by Regulatory T cells in ashtma Kerstin Wanke Ruth Ferstl Zsolt I Komlosi Maciej Chalubinski Paulina Wawrzyniak Michael B Soyka Stefan Soumlllner Liam OrsquoMahony Cezmi A Akdis Swiss Institute of Allergy and Asthma Research (SIAF) Davos Switzerland kerstinwankesiafuzhch The nature of the interplay between epithelium and resident T-cells is of great importance in allergic asthma Bronchial epithelial cells form an essential barrier that plays a key role in asthma-associated lung inflammation Tight junction (TJ) complexes are responsible for the integrity of epithelial cell barriers They form tight homodimeric cell-cell contacts and control cellular integrity polarity and paracellular flow of molecules and cells We investigated the regulation of TJ by regulatory T cells (Tregs) and their cytokines A broad spectrum of TJ protein genes were expressed in bronchial epithelial cells In total lung homogenates the pattern of TJ mRNA expression was different reflecting the multiple cell types present in whole tissue Following OVA-induced allergic airway inflammation in BALBc mice TJ mRNAs were down-regulated The adoptive transfer of CD4+CD25+ Treg cells prevented the down-regulation indeed TJ expression was increased The TJ expression levels showed a strong positive correlation with the levels of Treg cytokines IL-35 chains p35 and EBI3 as well as TGFbeta and a negative correlation with IFNgamma while there was no correlation with the Th2 cytokines IL-4 and IL-13 The intratracheal administration of Tregs was more effective in supressing eosinophilic infilatration airway inflammation and Th2 cytokine production than systemic administration of Treg cells Total protein concentration in BALF was more efficiently reduced as well indicating an increased epithelium integrity In conclusion we provide evidence for an additional and novel Treg protective mechanism against tissue inflammation which is exerted at the level of improved epithelial integrity and barrier function

Inhibitory Fcg Receptor Function In Autoimmune Neuroinflammation

Isaak Quast Falk Nimmerjahn Jan Luumlnemann

Department of NeuroinflammationInstitute of Experimental ImmunologyBuilding Y44 Room J88Winterthurstrasse 190CH-8057 Zuumlrich

IsaakQuastuzhch

The activation of autoreactive T and B cells and their recruitment into the central nervous system (CNS) are considered crucial events in the development and progression of multiple sclerosis (MS) How tolerance towards self antigens is maintained in healthy individuals and how autoreactive cells eventually become activated and perpetuate autoimmune CNS inflammation is incompletely understood Mice deficient in activating receptors recognizing the constant (Fc) fragment of IgG (FcgR) are protected from or develop less severe experimental autoimmune encephalomyelitis (EAE) pathology Here we hypothesize that the inhibitory Fcg (FcgRIIB) which counterbalances signals provided by activating FcgR in innate antigen-presenting cells (APCs) and prevents autoreactive B cells from becoming IgG positive plasma cells limits EAE pathologyTo test our hypothesis we will (1) determine whether FcγRIIB-deficiency accelerates EAE progression Using conditional gene targeting in mice and adoptive transfer experiments we will (2) further determine whether and by which mechanisms FcgRIIb-expressing APCs or B cells modulate EAE pathology We could previously show that sialylated Fc fragments and the presence of FcgRIIb mediate the anti-inflammatory activity of intravenous immunoglobulin (IVIG) To evaluate the therapeutic potential of FcgRIIb during T cell-mediated autoimmune CNS inflammation we will (3) investigate whether sialylated Fc fragments are equally effective or superior compared to conventional IVIG in ameliorating EAE pathology and whether the therapeutic efficacy of IVIG and sialylated Fc fragments require FcgRIIb expression These studies are expected to provide insights into an as yet unexplored potential mechanism of autoimmune CNS inflammation and may reveal new therapeutic targets in chronic autoinflammatory CNS diseases

Abstracts of Poster Presentations

Poster No Name

1 Andreacute Gladiator 2 Thomas Ammann 3 Daniel Andritschke 4 Dominik Aschenbrenner 5 Tess Brodie 6 Gerardo Caacutercamo 7 Josh Crouse 8 Thomas Edinger 9 Mattia Garbani 10 Christian Jenul 11 Marc Jordi 12 Patricia Krukowski 13 Duo Li 14 Nadezda Masloboeva 15 Marc Nischang 16 Helge Frebel 17 Julia Noack 18 Deepa Mohanan 19 Kerstin Weidner 20 Monika Nussbacher 21 Heike Nowag 22 Leontios Pappas 23 David Plaza 24 Moira Prati 25 Juumlrgen Rac 26 Mary-Aude Rochat 27 Katrin Schilcher 28 Kathrin Schneider 29 Wolfgang Kratky 30 Jenny Thom 31 Jessica Toller 32 Saskia Kreibich 33 Nejc Stopnisek 34 Tarik Azzi

Poster Session 1 poster 1-17 Poster Session 2 poster 18-34

CHARACTERIZATION OF CANDIDA ALBICANS SPECIFIC

T HELPER CELL RESPONSES

A Gladiator E Baumlr K Weidner S LeibundGut

ETH Zuumlrich Institute of Microbiology Wolfgang-Pauli-Str10 8093 Zuumlrich andregladiatormicrobiolethzch

Fungal infections gained increasing clinical relevance during the last decades Among the

causative agents of such infections is the fungus Candida albicans As a commensal it

colonizes skin and mucosal surfaces and can be isolated from the oral cavity in up to 80

of healthy individuals Those develop stable interactions with the fungus but in the

course of immunodeficiency (eg AIDS or immunosuppressive treatment related to organ

transplantation) it can convert to an opportunistic pathogen and may cause different forms

of candidasis as well as lethal systemic infections The immune response to such

infections is complex and incompletely understood as it not only depends on both innate

and adaptive immunity but also significantly varies depending on the site of infection The

involvement of CD4+ T cells and their pivotal role in protection is illustrated in HIV+

patients that predominantly develop oropharyngeal candidasis (OPC) Using a mouse

model of OPC we could show that in the course of infection C albicans-specific CD4+ T

cells are efficiently activated and primed to produce IL-17A IL-17F IL-22 and GM-CSF

but no IFN-γ or IL-4 Although the fungus is rapidly cleared to undetectable levels these

cells persist in the host while displaying a memory phenotype at 4 weeks post infection

We further aim at defining the effector functions antigen specificity as well as the

protective capacity of these C albicans-specific CD4+ T cells Finally the results shall

increase the understanding of immune responses to OPC and may all together offer

valuable insights for the development of novel anti-fungal therapy

Structural analysis of a subgingival biofilm model system Thomas Ammann Thomas Thurnheer Thimios Mitsiadis Jakob Pernthaler Zentrum fuumlr Zahnmedizin Plattenstrasse 11 8032 Zuumlrich tammannaccessuzhch

Periodontal disease caused by subgingival biofilms is a health issue occurring worldwide with serious consequences if not treated properly The enormous complexity of the microbial community in the oral cavity and the fact that these organisms form biofilms makes the disease both hard to treat and hard to study The aim of the current study is to provide a well characterized tool for research about such biofilms and the organization of some bacteria playing key roles in this community

Methods The presented in vitro biofilm model system consists of 10 organisms typically found in subgingival biofilms (Streptococcus oralis Streptococcus anginosus Veillonella dispar Actinomyces oris Fusobacterium nucleatum Campylobacter rectus Prevotella intermedia Tannerella forsythia Porphyromonas gingivalis and Treponema denticola) Biofilms are cultivated on hydroxy-apatite discs during 645 h of anaerobic incubation in a complex medium supplemented with specific growth factors for the bacteria used in the model

Results The current study gives insight into the three dimensional structure of such model biofilms using confocal laser scanning microscopy On the other hand different growth media were tested in order to obtain a community resembling the situation in vivo For this purpose abundances of the bacteria were determined by real-time PCR selective agars and indirect immunofluorescence

Conclusions Human serum was found to be an important factor to promote growth of bacteria associated with disease Streptococci play an important role as early colonizers of the biofilms and are required by bacteria colonizing at later stages

Genome wide RNAi screen to identify cellular components involved in SipA-mediated Salmonella Typhimurium invasion

Daniel Andritschke Sabrina Dilling and Wolf-Dietrich Hardt

Institute of Microbiology ETH Zurich

danielandritschkemicrobiolethzch

The enteropathogenic bacterium Salmonella Typhimurium is a common cause of gastroenteritis and can trigger pronounced mucosal inflammation Like many other pathogenic Gram-negative bacteria it employs a type III secretion system (TTSS) to inject effector proteins into host cells The effectors SopE SopE2 and SopB are injected by TTSS-1 These proteins stimulate actin rearrangement by interfering with Rho GTPase signaling The resulting pronounced actin polymerization leads to the formation of characteristic membrane ruffles facilitating Salmonella invasion On the contrary SipA directly binds to F-actin promoting local actin polymerization filament stabilization and bundling Recent research in our group shows that SipA efficiently mediates invasion in the absence of SopE SopE2 and SopB Furthermore internalization does neither require nor induce membrane ruffling and seems to be Rho-GTPase-dependent These results suggest a different strategy for SipA-mediated internalization compared to other effector proteins Using a genome wide siRNA screen we try to identify genes playing a role in this type of Salmonella invasion Cellular components interacting with SipA and SipA-mediated entry will be characterized using cell biology methods to eventually gain more insights into this mechanism

Regulation of cytokine gene expression in human effector and memory T cells Dominik Aschenbrenner Christina Zielinski Federica Sallusto Antonio Lanzavecchia Institute for Research in Biomedicine (IRB) Via Vincenzo Vela 6 CH-6500 Bellinzona dominikastudentethzch TH17 cells represent a distinct lineage of CD4+ T helper cells characterized by the production of IL-17A IL-17F and IL-22 that are involved in autoimmunity as well as in host defence Groundbreaking studies showed that IL-6 and TGF-β initiate mouse TH17 differentiation which is reinforced by IL-23 leading to acquisition of pathogenic activity in models of autoimmunity In humans TH17 differentiation is induced by IL-6 IL-1β and IL-23 while TGF-β may play enhancing or inhibitory roles depending on the concentration used during stimulation Using an in vitro T cell priming method we recently found that CA primes TH17 cells producing IL-17 and IFN-γ but no IL-10 in an IL-1β-dependent fashion while Staphylococcus aureus (SA) primes TH17 cells producing IL-17 and IL-10 but no IFN-γ in an IL-1β-independent fashion These pathogen-specific cytokine signatures were also detected in ex vivo isolated memory TH17 cells indicating that the in vitro priming recapitulates the essential elements of the in vivo priming Production of IL-10 by SA-specific TH17 clones was dependent on the activation state and was inhibited when restimulation was performed in the presence of IL-1β These findings demonstrate the existence of at least two distinct human TH17 subsets that differ in IL-10 production microbial specificity and priming requirement The above results suggest that the IL-17 to IL-10 switch in activated TH17 cells may represent a novel mechanism of immune regulation whereby continuous antigenic stimulation triggers in effector T cells a late self-regulatory anti-inflammatory response

Longitudinal analysis of the immune response of human CD4+ T cells to an influenza vaccine Tess Brodie Antonio Lanzavecchia Federica Sallusto Institute for Research in Biomedicine Via Vincenza Vela 6 6500 Bellinzona CH Tessbrodieirbunisich Memory CD4 T cells specific for influenza virus are generated from natural infection and vaccination and persist long-term Tracking diverse subsets of T helper cells at different time points during influenza vaccination in human can provide insights on which T cell subsets are important for immune response to influenza A virus Our aim is to study influenza-responding cells in diverse T cell subsets over a vaccine time course Using the CD4 T cell library method developed in the laboratory we compared the repertoire of naiumlve (TN) circulating follicular helper T cells (TFH) central memory T cells (TCM) and effector memory T cells (TEM) before 7 and 15 days after an immune challenge with Influvac a seasonal influenza vaccine We will report data on the distribution and responsiveness of specific T cells in the different subsets and how the response changes with time Understanding the dynamics of antigen-specific T cells in naiumlve effector and memory subsets can give insight to the mechanisms of clearance for specific pathogens and reveal correlates of protection

Biosurfactans and bacterial motility roles on Biofilm Development in

Pseudomonas putida IsoF

G Caacutercamo-Oyarce P Lumjiaktase and L Eberl

gerardocarcamo-oyarceuzhch

Microbiology Department Plant Biology Institute UZH Zollikerstrasse 107

CH-8008 Zuumlrich

In nature most of bacteria live in close association with surfaces as complex

communities referred to as biofilms Biofilm formation is a complex phenomenon which

involves the integration of environmental and cellular signals into an intricate regulatory

network leading to the adaptation of bacteria to multicellular life on a surface

We focused on the biofilm formation process of plant-promoting bacterium P putida

IsoF We investigated the role of quorum sensing-regulated factors (involved on biosurfactant

production putisolvin I and II) and bacterial motility on several biofilm development stages

Through the use of flow cell technology and confocal laser scanning microscopy we

found that the wild type strain formed a rather flat and confluent biofilm with only few

microcolonies whereas a putisolvin- defective strain formed clearly visible microcolonies and

the void space between them was poorly colonized These results suggest that the

putisolvins produced by P putida IsoF enable the surface colonization probably by

facilitating the detachment and outwards movement of cells from microcolonies On the other

hand the flagella-defective strain was found to be deficient in the initial phase of biofilm

formation and the microcolonies that eventually formed were more compact than the ones of

the wild type We further confirmed these data through two-color-coded mixed-strain biofilms

These results contribute to elucidate the mechanisms involved on biofilm formation

and development which is essential for designing effective strategies to control biofilms or to

optimize the beneficial applications of them

DIRECT TYPE I IFN SIGNALING DETERMINES THE CELL FATE DECISION

BETWEEN SHORT-LIVED EFFECTOR CELLS AND MEMORY PRECURSOR

EFFECTOR CELLS

Josh Crouse Melanie Wiesel and Annette Oxenius Institute of Microbiology ETH Zurich joshcrousemicrobiolethzch The formation of effector and memory CD8 T cell subsets is a complex and not well

characterized event Two subsets of CD8 T cells are generated shortly after activation

one of these subsets preferentially forms the memory pool known as memory precursor

effector cells (MPEC) and the other subset is destined to become terminally differentiated

effector cells known as short lived effector cells (SLEC) Multiple factors have been

shown to play important roles in the fate decision between MPEC and SLEC but these

factors vary greatly depending on the infection model used

Here we have studied the role of type I IFNs on the early effector and memory CD8 T cell

differentiation following a coinfection with LCMV and Vaccinia virus (VV) We found that

as early as day 6 post infection IFNAR-deficient CD8 T cells exhibit a MPEC phenotype

(KLRG1low CD62Lhigh IL7Rahigh CD25low and T-betlow) rather than a SLEC phenotype as

seen for wild type CD8 T cells Furthermore the MPECs formed in the absence of type I

IFN signaling were long lived and functional This data further clarifies the complex

process of CD8 T cell differentiation and indicates that upon infections associated with

early and abundant type I IFN production direct type I IFN signaling on CD8 T cells is

necessary for the differentiation of SLEC

Human host factors involved in influenza A virus entry Thomas Edinger amp Silke Stertz Institute of Medical Virology

University of Zuumlrich

Winterthurerstrasse 190

CH-8057 Zuumlrich

E-mail edingerthomasvirologyuzhch

For the entry process of Influenza A virus (IAV) a broad range of particular host factors is

required This is due to the fact that IAV has only a small coding capacity with its (-)ssRNA

genome and for the entry and following replication it is dependent on a repertoire of host cell

proteins By performing genome wide siRNA screens several of these host factors were

identified to exhibit crucial functions within the replication cycle of IAV and especially during

the entry process of IAV into a susceptible target cell Among these proteins were particular

candidates with distinct biological functions such as surface receptors kinase-regulated

signaling or proteins involved in ubiquitination and phosphatase activities For a small

number of genes out of a large pool of 295 candidates it was shown that siRNA-mediated

knock-down of a certain gene resulted in impaired virus entry Within this project the 23

ldquoentry candidatesrdquo are going to be analyzed for their effect on a particular target step during

IAV entry in lung epithelial cells The entry process of IAV will be subdivided in four different

entry steps from the viral attachment to the host cell membrane to the process of

endocytosis endosome maturation and finally the fusion of the viral membrane with the

endosome membrane The overall goal is to identify host factors that are crucial for a

particular step within the entry process for Influenza A virus and represent suitable targets for

future antiviral therapy

Direct targeting of dendritic cells as a novel concept for allergen-specific immunotherapy

Mattia Garbani Claudio Rhyner Reto Crameri

Swiss Institute for Allergy and Asthma Research (SIAF) University of Zuumlrich Oberestr 22 Davos Switzerland mattiagarbanisiafuzhch Allergic diseases develop from a disregulated TH2 dominated immune response leading to the production of IgE against normally innoquous environmental antigens Todays therapies for allergic diseases aim to induce a switch towards a TH1Treg dominated immune response by challenging the patient with increasing doses of allergen The current approach has two major disadvantages the duration of the treatment (up to 5 years and 100 injections) and the anaphylactic side-effects The Modular Antigen Translocation (MAT) Vaccine exploits the ability of a HIV-TAT (Trans Activator of Transcription) derived peptide to bring recombinant antigens linked to a portion of invariant-Chain (Li) into cells Li targets the immunogenic protein directly to MHC-II therefore i) less antigen is needed leading to reduced side-effects and ii) the number of injections needed is reduced resulting in a better patientrsquos compliance MAT vaccines are potentially internalized in every cell and are terefore not able to specifically target antigen presenting cells The aim of the project is to create a new generation of vaccines where the TAT peptide is substituted or supplemented by newly discovered peptides able to specifically target dendritic cells the most potent antigen presenting cells Using Green Fluorescent Protein fusions as a model system we were able to confirm the specific targeting of the DC-specific peptide pep3 to DCs In the next stage pep3 will be fused with the major cat allergen Feld1 The capability of pep3-Feld1 primed DCs to induce the desired shift on cytokine patterns towards a Th1Treg phenotype will be assessed in cell co-culture with T-cells and the in vivo efficacy of the newly engineered vaccines will be determined in a mouse model of allergy

Quorum sensing in the plant symbiont Burkholderia kirkii Christian Jenul1 Aurelien Carlier1 and Leo Eberl1 1Department of Microbiology Institute of Plant Biology University of Zuumlrich Zuumlrich Switzerland Contact christianjenulbotinstuzhch Burkholderia kirkii is a symbiotic bacterium inhabiting the leaves of the plant Psychotria kirkii

The relationship between these two organisms is a closed symbiotic cycle ie the bacteria

are transferred from one plant generation to the next via the seeds and remain throughout

the life-cycle of the plant Loss of the bacterial symbiont eventually leads to death A quorum

sensing (QS) cluster and two aminocyclitol clusters are present on a 130 kb plasmid in B

kirkii The QS system consists of two components an acylhomoserine lactone (AHL)

synthase LuxI and an AHL receptor LuxR which can act as a transcription factor

Aminocyclitols exhibit a broad spectrum of activities including killing of bacteria and fungi

The hypothesis for my project is that the molecule produced by the aminocyclitol clusters

plays a role in the symbiosis of B kirkii and P kirkii Furthermore we propose that the

aminocyclitol clusters are QS regulated indicating that the QS system of B kirkii is important

for symbiosis Initial results show that the AHL synthase of Bkirkii produces AHLs and thus

is active Promoter fusion studies of the putative luxI and luxR promoter regions showed no

autoregulation of the QS cluster Investigation of the mechanism of regulation of the

aminocyclitol clusters is currently in progress and should allow us to determine whether

these clusters are regulated via the QS system in B kirkii

TLR9 signaling regulates EBV lytic gene expression via posttranslational modifications

Marc Jordi Ludwig Zauner Marta Wehrmuumlller Natascha Andrea Wuillemin Juumlrg A Sigrist Christoph Berger Michele Bernasconi David Nadal Experimental Infectious Diseases and Cancer Research Childrenrsquos Research Center University Childrenrsquos Hospital Zuumlrich August-Forel-Strasse 1 8008 Zuumlrich marcjordikispiuzhch Tel +41-44-634-8834

Abstract

Background The Epstein-Barr virus (EBV) immediate-early protein Zta that is encoded by

BZLF-1 mediates the switch between EBVrsquos latent and lytic state and TLR9 triggering can

down-regulate Zta expression in a MyD88 dependent but NF-κB independent manner

Methods Akata Burkitt lymphoma B cells latently infected with EBV and which can be

induced to produce Zta were treated with cycloheximide an inhibitor of protein synthesis

and with histone deacetylase inhibitors Chromatin immunoprecipitation against acetylated

and phosphorylated histones was performed to assess chromatin status after TLR9

triggering condition

Results We found that TLR9-induced BZLF1 down-regulation does not require protein

synthesis following triggering Treatment of Akata cells with histone deacetylase inhibitors

rescued BZLF1rsquos mRNA expression which strongly suggests that TLR9 induces histone

modification(s) on BZLF1rsquos Zp promoter and by the way mediates the suppression of lytic

EBV This was quantitatively confirmed by chromatin immunoprecipitation We demonstrated

that genomic BZLF1 and BZLF1rsquos Zp promoter sequences placed on a pHEBo luciferase

reporter plasmid are regulated differently after TLR9 triggering Histones of the genomic

BZLF1 are deacetylated when TLR9 is activated prior to lytic EBV induction which is not

observed for the pHEBo luciferase reporter plasmid where the acetylation levels of the

histones remained unchanged

Conclusion TLR9 activation affects the chromatin structure of EBVrsquos immediate-early lytic

gene BZLF1 at least partly in a protein synthesis independent manner and thus promotes

EBV latency We hypothesise that additional epigenetic mechanisms are involved

Susceptibility of B cell subsets to infection by Epstein-Barr virus (EBV) relates to

integrin expression pattern

Patricia Krukowski Michele Bernasconi and David Nadal

Experimental Infectious Diseases and Cancer Research University Childrens Hospital of Zurich UZH University Childrens Hospital of Zurich Experimental Infectious Diseases and Cancer Research August Forel Str 1 CH-8008 Zuumlrich email patriciakrukowskikispiuzhch

Entry of EBV into B-cells depends on the interactions between EBV gp350220 and CD21

plus EBV gp42 and HLA class II molecules szlig1 integrin seems crucial in determining

enhanced entry but the role of other integrins is unknown

Susceptibility of B cells to EBV B958 infection was assessed by a newly established assay

combining in-situ hybridization using a fluorescent DNA probe for EBV non-coding RNA-1

(EBER-1) that is expressed in every EBV-infected cell and flow cytometry Expression of

integrin mRNA was quantified by real-time PCR in primary B cells and B cell lines including

Raji that is readily infectable with EBV

Memory B cells from palatine tonsils were found more susceptible to EBV infection than their

naiumlve counterparts The difference could not solely be explained by distinct szlig1 integrin

expression Integrin expression patterns from primary B cells and Raji B cells were

qualitatively and quantitatively similar Their patterns differed substantially from those of B

cell lines exhibiting lower susceptibility to EBV infection

Our observations suggest candidate integrins that in addition to szlig1 integrin may contribute to

distinct susceptibilities of B cell subsets to EBV infection

Role of Suppressors of Cytokine Signalling (SOCS)-1 and -3 in HIV

Duo Li1 Erika Schlaepfer1 Gustavo Gers-Huber1 Roberto F Speck1

Division of Infectious Diseases and Hospital Epidemiology Raemistrasse 100 University

Hospital of Zurich University of Zurich Switzerland

Background SOCS play a prominent role in the negative regulation of cytokine signalling

and thus immune activation We have previously shown that SOCS are deregulated in

natural HIV infection and is not able to counteract HIVrsquos immune activation that is a main

trigger for HIVrsquos associated immunodeficiency The regulation of SOCS in human remains

largely unknown since it has investigated mainly in mice My goal is to characterize cellular

factors acting on the promoter activity of SOCS-1 and -3 in the human context

Results For that purpose I will establish a cell-based assay with a reporter gene for medium

throughput screen (MTS) of a compound library For identifying the optimal cells I examined

the kinetic of mRNA expression of SOCS1 and -3 in primary cells and in a panel of cell lines

in response to IFN- or IFN- Sup-T1 and THP1 show a rapid and distinct INF-dependent

increase of the SOCS mRNA permitting efficient MTS I am currently sub-cloning the

lentiviral vector constructs containing the SOCSrsquo gene regulatory sequences driving

luciferase which subsequently will permit to generate stably transduced cells

Outlook In the near future I will validate the cell based assay and adapt it to a 96-well

format Key steps will be the MTS and the elucidation of the molecular mechanism(s) of hits

from the MTS

Bradyrhizobium japonicum extracytoplasmic function (ECF) sigma factors involved in symbiosis and oxidative stress response Nadezda Masloboeva Luzia Reutimann Hans-Martin Fischer Socorro Mesa and Hauke Hennecke ETH Institute of Microbiology Zuumlrich Switzerland nadezdamasloboevamicrobiolethzch The nitrogen-fixing soybean symbiont Bradyrhizobium japonicum encodes 23 sigma factors two belonging to the sigma-54 and 21 to the sigma-70 family In the latter group 17 so-called extracytoplasmic function (ECF) sigma factors are found whose functions are largely unknown Using a functional genomics approach in combination with transcriptional profiling we are studying the role of selected ECF sigma factors Special focus is on sigma-EcfG which is required for an efficient symbiosis (1) and three additional sigma factors (Blr1028 Blr3038 Blr3042) that are involved in the response of B japonicum to oxidative stress EcfG is regulated by an anti-sigma factor (NepR) and an anti-anti-sigma factor (PhyR) via a mechanism that appears to be specific for alpha-proteobacteria (2) Blr1028 and Blr3038 are both induced by H2O2 respective mutants show a distinct phenotype with respect to their sensitivity to different reactive oxygen species The regulons of these sigma factors are currently being determined to identify common and specific target genes Unlike blr1028 blr3038 is associated with a predicted anti-sigma factor gene whose product is likely to regulate Blr3038 in response to oxidative stress Although host legume plants are known to exert oxidative stress on infecting rhizobia mutants lacking blr1028 or blr3038 are symbiotically proficient 1 Gourion et al Mol Microbiol 73291-305 2009 2 Francez-Charlot et al pp 291-300 in Bacterial Stress Responses (G Storz and R Hengge eds) ASM Press 2011

Novel concept of long-acting anti-retroviral drugs for the treatment of HIV-1 infection

Marc Nischang1 Gustavo Gers-Huber1 Annette Audige1 Erika Schlaepfer1 Stefan Baenziger1 Ursula Hofer1 Stephan Regenass2 Jacques Bollekens3 Guenter Kraus3 Daniel Boden3 Roger Sutmuller3 Roberto Speck1 1Division of Infectious Diseases 2Institute of Clinical Immunology University Hospital Zurich Switzerland and 3Tibotec BVBA Beerse Belgium Division of Infectious Diseases and Hospital Epidemiology University Hospital Zurich Raumlmistrasse 100 CH-8091 Zuumlrich Switzerland marcnischanguszch Here we report about the utility of a HIV mouse model which is based on the transplantation of human CD34+ cells into immunocompromised mice for testing novel anti-retroviral treatment strategies Pharmacokinetic testing was performed to determine the optimal dosing for TDF and 3TC gauged by consumption of food pellets with drugs contained therein and for the two long-acting (LA) drugs TMC278 (NNRTI) and TMC181 (PI) administered sc once weekly In a 1st experiment treatment with TDF 3TC and TMC278-LA resulted in suppression of HIV RNA to below detection limit of 800 copiesml in 1421 (666) mice six weeks after treatment start Interruption of ART resulted in viral rebound consistent with the existence of a latent reservoir The partial treatment response was most likely due to emergence of resistant isolates due to an initially insufficient regimen with AZT (toxicity) 3TC and Ritonavir (insufficient drug levels) which was switched after 2 weeks to the above described regimen In a 2nd experiment treatment with TDF 3TC TMC278-LA and TMC181-LA for 7 weeks resulted in viral suppression in 1012 (833) mice Simplification of ART by administering solely the two LA-compounds kept HIV suppressed in 56 (833) mice (here detection limit was lt60 copiesml) CD4+ T-cells clearly recovered in all treated mice In summary HIV-infected humanized mice recapitulate cardinal features of HIV infection namely sustained and disseminated infection and importantly viral rebound after interruption of ART Here we report the successful application of a novel concept of ART based on the administration of long-acting drugs

Programmed death 1 protects from fatal circulatory failure after systemic virus infection

Helge Frebel Reto Schuumlpbach Kirsten Richter Johannes Vogel and Annette Oxenius

Swiss Federal Institute of Technology Zurich Institute of Microbiology

frebelmicrobiolethzch

By infecting mice with lymphocytic choriomeningitis virus (LCMV) a resolved or chronic

infection can be induced depending on the viral strain and the dose of infection Chronic

LCMV infection is marked by the functional downregulation of T cells which is characterized

by a strong reduction of cytokine secretion a reduced capability to proliferate and an

impaired memory development To date it remains controversial if the functional loss of

virus-specific T cell immunity represents an immunoevasive mechanism of the pathogen or if

T cell function is downregulated as an endogenous mechanism to prevent

immunopathology

Recent studies suggest the upregulation of the immunoinhibitory receptor programmed

death 1 (PD-1) by virus-specific T cells to be intimately linked to their progressive loss of

function during chronic LCMV infection Interestingly the induction of a chronic LCMV

infection in PD-1-- mice is fatal within 7 days implying this immunoinhibitory receptor to play

a protective role and shedding light on a possibly protective function of T cell

downregulation

This project aims at investigating the role of the PD-1PD-L pathway during the early phase

of chronic LCMV infection in terms of determining the impact of PD-1 deficiency on virus-

directed immune responses and elucidating the immunological processes that lead to

fatality We show that the lack of PD-1 expression significantly enhances CD8 T cell function

and that PD-1 deficiency exclusively on CD8 T cells is sufficient to drive pathology Fatality is

marked by a perforin-dependent increase of vascular permeability as a result of a

compromised vascular endothelial integrity This ultimately leads to hypothermia the

formation of pulmonary edema and a fatal breakdown of circulation

Role of the SEL1LLC3-I complex as an ERAD tuning receptor in the mammalian ER Julia Noack Riccardo Bernasconi Carmela Galli Siro Bianchi Maurizio Molinari Institute for Research in Biomedicine Via Vincenzo Vela 6 6500 Bellinzona Switzerland julianoackirbunisich In the endoplasmic reticulum (ER) the conformational maturation of nascent polypeptides and their

recognition for ER-associated degradation (ERAD) are in kinetic competition The low basal level

of ERAD regulators in unstressed cells prevents inappropriate interruptions of folding programs

and degradation of not-yet-native folding intermediates With a variety of poorly characterized

mechanisms crucial for cellular proteostasis ERAD Tuning regulates the selective removal from

the ER of proteins such as EDEM1 OS-9 ERManI SEL1L HERP gp78 which at steady state

are characterized by faster turnover compared to conventional ER chaperones We found that in

unstressed cells the two ERAD regulators EDEM1 and OS-9 are segregated in ER-derived

vesicles and are degraded by lysosomal proteases Here we identify the complex comprising

SEL1L and the cytosolic-associated ubiquitin-like protein LC3-I as the membrane receptor that

regulates the intraluminal content of EDEM1 and OS-9 at the post-translational level by promoting

their COPII-independent vesicular export from the ER folding environment

Photochemical Internalisation A ray of hope Deepa Mohanana Paringl K Selbob Kristian Bergb Anders Hoslashgset c Thomas Kuumlndiga and Paringl Johansena

aDepartment of Dermatology University Hospital of Zuumlrich Switzerland bDepartment of Radiation Biology Oslo University Hospital cPCI Biotech Lysaker Norway DeepaMohananuszch

Immunotherapy to combat tumours or chronic infectious disease need to stimulate cytotoxic CD8 T-cell responses Whilst some vaccines have shown potentials in animals the same strategies in humans often fail to induce a potent protective and especially therapeutic immune response One plausible explanation for this poor efficacy is the difficulty in delivering enough antigen to the MHC-class I pathway of antigen presentation Usually antigens are taken up by antigen presenting cells (APCs) by endocytosis Inside the cells the resulting endosomes then mature and fuse with the lysosomes causing the antigen to be digested and presented by the MHC-class II pathway For the induction of CD8 T-cell responses the endocytosed antigen have to be delivered to the MHC-class I pathway Many strategies are currently under study to better target antigen to the MHC class I processing machinery One such potential strategy is photochemical internalisation (PCI) PCI involves using a chemical photosensitiser that localises to the cell membrane and becomes activated upon exposure to an appropriate light source which leads to bursting of the membrane of endosomes thereby releasing the drug If this can be achieved prior to lysosomes fusion it is possible to release high doses of antigen into the cytosol However intracellular dose of antigen achieved by conventional methods is typically low and by consequence also limiting the efficacy of vaccinations Therefore the objective of this project is to combine PCI with microparticles to deliver high antigen doses effectively to the MHC class I pathway

Antigen presenting cells involved in Th17 cell priming during Candidiasis

Kerstin Weidner1 Andreacute Gladiator1 and Salomeacute LeibundGut-Landmann1

1Institute for Microbiology ETH Zurich Wolfgang-Pauli-Strasse 10 HCI G435 8096 Zurich

Switzerland

kerstinweidnermicrobiolethzch

The fungus Candida albicans lives as part of the normal microflora in healthy individuals

without triggering any harmful effects However it can cause severe disease in

immunocompromised individuals The increased prevalence of mycoses such as

orophangyngeal candidiasis (OPC) in AIDS patients provides evidence for CD4+ T cells

playing a key role in protection from fungal diseases C albicans-specific CD4+T cells are

primed efficiently in response to oropharyngeal infection in mice and these T cells produce

high levels of IL-17A and other Th17-type cytokines However it remains unclear which

subset(s) of antigen presenting cells (APCs) mediate this efficient T cells priming during

OPC Here we show that among others monocyte-derived DCs (MoDCs) infiltrate strongly

into the draining lymph nodes during infection suggesting that they mediate directly or in

cooperation with lymph node-resident APCs the priming of Candida-specific Th17 cells

MoDCs indeed present Candida-derived antigens in the draining lymph nodes of infected

mice as they are able to activate Candida-specific T cell hybridoma ex vivo The role of

MoDCs for the activation of Candida-specific T cells during OPC in vivo is being confirmed

Together this study shall illuminate and extend the prominent function of MoDCs as

activators of the adaptive immune system that has recently been attributed to them in

various tissues including the lung to the oral cavity another prominent site of pathogen

Modulation of coronavirus vector-induced immune responses

Monika Nussbacher Luisa Cervantes-Barragan Roland Zuumlst Eva Allgaumluer Reinhard Maier Burkhard Ludewig and Volker Thiel

Institute of Immunobiology Kantonal Hospital St Gallen Switzerland

Targeting of antigen to dendritic cells (DCs) in vivo can be achieved by several means whereby

the use of viral vectors appears to be the superior strategy to elicit innate activation of the

immune system and optimal induction of CD8+ T cells We recently described a novel

coronavirus-based vaccine approach that facilitates delivery of viral or tumor antigens to DCs in

vivo (Cervantes-Barragan et al mBio 2010) In order to modulate vaccine-induced immune

responses we demonstrate here that concomitant immunomodulation can be achieved by

vector-mediated expression of cytokines GM-CSF IL-2 IL-15 IL10 and Flt3L Single

immunization with only 104 ndash 105 GM-CSF-encoding coronavirus-based particles was sufficient

to elicit (i) vigorous expansion and optimal differentiation of CD8+ T cells (ii) protective and

long-lasting antiviral immunity and (iii) prophylactic and therapeutic tumor immunity Taken

together we have developed a novel coronavirus-based vaccine approach that facilitates

antigen delivery to DCs and allows for immunomodulation through expression of co-stimulatory

cytokines

Regulation of macroautophagy during lytic EBV infection

Heike Nowag Christian Muumlnz

Institute of experimental Immunology Winterthurerstrasse 190 8059 ZuumlrichHeikeNowagneuroimmuzhch

Macroautophagy is a cellular degradational system which in contrast to the ubiquitin-proteasomal pathway engulfs long-lived proteins and organelles in a characteristic double-membrane vesicle Subsequently this vacuole fuses with lysosomes in order to break down the cargo This degradation system is upregulated following stress responses to nutrients deprivation or insults by intracellular pathogens Several pathogens have evolved strategies to inhibit or exploit this pathway for a successful replication within the host cell On the other hand an upregulation of autophagy by the host cell may also be used to enhance the viral clearance Epstein Barr virus is a y-herpesvirus and as such contains classical viral latency features with reversibility as a hallmark (lytic phase) To date little is known about the relationship between the lytic phase of Epstein Barr virus (EBV) infection and macroautophagy

THE EFFECT OF PASSIVE SEROTHERAPY ON THE IMMUNE RESPONSE TO INFLUENZA Leontios Pappas Andrea Minola Davide Corti Federica Sallusto and Antonio Lanzavecchia Institute for Research in Biomedicine Bellinzona Switzerland Objectives The object of our study is to determine the effects of administration of broadly neutralizing antibodies against the stem of influenza HA proteins in protecting from disease pathology and directing the development of B cell memory in infected or vaccinated animals To achieve this aim we are developing an in vitro quantitative assay to measure the frequency and specificity of mouse memory B cells after infection or vaccination Materials and Methods 6-8 week old female BALBc mice infected sub-lethally with APR8 influenza were treated with the HA-binding FI6 antibody Serum antibody responses were measured by ELISA and the neutralization potency of the sera was quantified using a luciferase reporter assay for viral neutralization of APR8 In order to measure the frequency of antigen specific B memory cells lymphocytes from the draining lymph nodes and spleen were cultured in media containing different cytokines TLR ligands or antibodies Antibody secretion in the supernatant was quantified by ELISA Results Intravenous administration of 1mgkg of the HA binding antibody FI6 to 6-8week old BALBc mice infected

with APR8 influenza is sufficient to prevent disease symptoms in mice and allows for the generation of

memory B cells that produce high amounts of antigen specific neutralizing IgG antibody with a mean EC50

titer of 124x103 and mean IC90 titer of 1265x103 recorded up to 5 months post-infection In certain mice

administration of doses of antibody higher than 5mgkg results in an endogenous heterosubtypic IgG

response as measured by serum binding to H5 pseudoparticles Optimal elicitation of antigen specific

memory B cell responses was obtained by stimulation with two TLR ligands CD40 antibody and a B cell

receptor antibody

Protein mediated defense strategies in fungi David F Plaza Markus Kunzler Markus Aebi Institute of Microbiology Swiss Federal Institute of Technology Zurich (ETHZ) Wolfgang-Pauli Strasse 10 HCI F420 Zurich davidplazamicrobiolethzch In nature nematodes develop complex predation and parasitism interactions with fungi plants and vertebrates Fungi have tuned a full arsenal of molecular effectors involved in defense and predation comprising proteases protease inhibitors and lectins among others The evidence currently available suggests that expression of nematotoxic fruiting body lectins (CGL1 and CGL2) is induced in the basidiomycete Coprinopsis cinerea upon challenge with the fungal-feeding nematode Aphelenchus avenae showing that genome wide a defense program comprising a broad variety of defense effectors might be triggered In addition many fungal lectins are strongly upregulated in fruiting bodies or sclerotia compared to vegetative mycelium encouraging us to explore the fruiting body transcriptome in the search for new defense candidates Genome-wide transcript expression of C cinerea AmutBmut fruiting body and mycelium was determined by deep RNA sequencing (RNA-seq) Upregulation of all the defense genes characterized until now by our group such as Mubin CCL2 CCL1 PIC CGL3 CGL2 and CGL1 was observed in fruiting bodies Some other loci that might entail a defensive role in C cinerea and comprehending unexplored functional classes such as CC1G_11630 (analog to MACPFperforin like protein from Photorhabdus luminiscens) and CC1G_10318 (protein similar to Aeromonas hydrophila Aerolysin) were found to be highly expressed in fruiting bodies too RNA-seq was shown to be a potent tool for the search of new defense effectors in fungi with potential applications in biomedicine and agriculture

Towards human allergen-specific monoclonal antibodies of the IgE isotype

Moira Prati Claudio Rhyner Reto Crameri

Swiss Institute for Allergy and Asthma Research (SIAF) University of Zuumlrich Davos moirapratisiafuzhch

In industrialized countries approximately 30 of the population is affected by IgE-mediated allergies including asthma atopic dermatitis or allergic rhinoconjunctivitis Allergen-specific IgE is the key molecule in allergic diseases and it can be expressed either as secreted IgE (sIgE) or as membrane-bound form (mIgE) which contains two additional domains termed M1 and M2 The M1 region codes for an extracellular membrane-proximal domain (EMPD) and for the transmembrane domain whereas the M2 region codes for the cytoplasmic domain expressed only in memory B cells as integral part of the B cell receptor (BCR) Hence specific targeting of mIgE on memory B cells could be a useful strategy for prophylactic therapeutic interventions

The main purpose of my research project is principally to demonstrate that α-EMPD mAbs can be used to isolate IgE-switched memory B cells from blood of allergic patients and to generate clones producing human allergen-specific mAbs of the IgE isotype by immortalization The long term goal of this project will be to co-crystallize allergens and allergen-specific human Fab fragments to elucidate IgE-binding epitopes In a complementary project IgE is directly targeted by addressing the MHC class-II antigen presentation pathway with the help of modular antigen translocation (MAT)-constructs which will then be tested in an in vivo murine model of allergy to demonstrate that humoral immune responses against self antigens can be elicited As candidate peptides the EMPD region of

mIgE and the mouse-Cε23 (mCε23) region responsible for the binding of IgE to its high affinity receptor will be used to induce an antibody response by vaccination With this approach we want to target and deplete IgE+ memory B cells reducing therefore the serum IgE levels without affecting the production of other antibody classes and deplete sIgE in order to reduce allergy symptoms

The longevity enzyme hTERT increases susceptibility of epithelial cells to infection by

Epstein-Barr virus

Juumlrgen Rac Roberto F Speck Michele Bernasconi David Nadal

Experimental Infectious Diseases and Cancer Research

Childrenrsquos Research Center University Childrenrsquos Hospital of Zurich UZH

August-Forel Str 1 8008 Zurich

juergenrackispiuzhch

Tel +41-44-6348834

Abstract

Epstein-Barr virus (EBV) is a γ-herpesvirus that enters its host through mucosal

epithelium and is associated with epithelial malignancies including nasopharyngeal and

gastric carcinoma The attachment and entry mechanisms of EBV into epithelial cells remain

mostly elusive although integrins might contribute to these processes Expression of the

longevity enzyme hTERT impacts on the susceptibility to infection of endothelial cells by

Kaposi sarcoma-associated herpesvirus another γ-herpesvirus

To test whether hTERT expression increases EBV infection susceptibility of epithelial

cells we generated stably hTERT-overexpressing HEK293 and AGS cell lines by retroviral

transduction hTERT-overexpression was confirmed by immunofluorescence microscopy and

flow cytometry Infection studies were performed using the recombinant EBV strain

B958EBfaV-GFP expressing eGFP constitutively which allowed determining the infection

frequencies by flow cytometry We further investigated the endogenous hTERT and integrin

expression in different epithelial cell lines by flow cytometry and qPCR respectively

hTERT-overexpressing epithelial cells showed an increased susceptibility to infection by

EBV of up to 35-fold compared to their parental counterparts Among the tested cell lines

HONE-1 showed the highest hTERT expression as determined by flow cytometry and the

highest mRNA expression of αV α3 α5 β1 β3 and β5 integrins

Thus the susceptibility of epithelial cells to infection by EBV may correlate with hTERT

expression We will confirm and expand our findings in primary epithelial cells and hTERT or

dominant negative (DN)hTERT-overexpressing cells by integrin blocking experiments

Promising role of Toll-like receptor (TLR) agonist in concert with compounds acting directly at the transcriptional level for purging the latent reservoir of HIV

Mary-Aude Rochat Erika Schlaepfer Roberto F Speck Division of Infectious Diseases and Hospital Epidemiology University Hospital Zurich Raumlmistrasse 100 CH-8091 Zuumlrich Switzerland Mary-Auderochatuszch Anti-retroviral treatment (ART) while very efficient in suppressing HIV replication will not cure HIV infection its interruption results in rapid HIV rebound from the latent reservoir Eradication of this latent reservoir is mandatory for a definite cure We hypothesize that triggering the immune system in concert with transcriptional enhancers will be a promising concept for purging the latent reservoir either by inducing viral cytopathic effects or by fostering HIV-specific CD8+-cytotoxic T-cells Compounds acting directly at a transcriptional level or indirectly via signalling pathways were screened first in latently infected T-cells (J-Lat) for their potency to reactivate transcription with a minimal toxicity TLR84agonists act primarily on myeloid dendritic cells (mDC) resulting in a change in the microenvironment favourable for mounting an immune response Thus we tested our concept subsequently in co-cultures of mDC and J-Lat cells for their purging potency We found that Prostratin (PKC activator) TLR4 and -8 agonists when given separately activated HIV transcription only moderately (~7 ~10 and ~2 respectively) However combining TLR4 or TLR8 agonist with prostratin resulted in a synergistic reactivation of ~40 and ~30 respectively We postulate that mDC activation will first increase the HIV reactivation through cytokine secretion such as TNF- and by inducing a TH1 response being favourable for fighting HIV Addition of transcriptional enhancers will result in a synergistic activation of latently infected cells The next steps in this work entail screening of further compounds a detailed mechanistic work-up of the treatments as well as an in vivo proof-of-concept in humanized mice

Visualization and quantification of neutrophil extracellular traps stimulated by bacteria

Schilcher K1 Uchiyama S1 Andreoni F1 and Zinkernagel AS1 1 Division of Infectious Diseases and Hospital Epidemiology University Hospital Zuumlrich Switzerland

Contact katrinschilcheruszch

Neutrophils are the first line of defense against infection and are therefore considered to be the most

important cells involved in innate microbial killing One of the mechanisms by which neutrophils can

kill bacteria is the formation of neutrophil extracellular traps (NETs) NETs represent complexes of

nuclear or mitochondrial DNA and proteins such as histones cell-specific proteases and antimicrobial

peptides It was shown previously that the human pathogen Group A Streptococcus (GAS) has the

ability to induce NETs formation in neutrophils We propose to explore the GAS-NETs interaction

using immunofluorescence to gain insights into NETs entrapment and additional factors that might

promote resistance against NETs-mediated killing of bacteria

Accordingly different techniques to visualize and evaluate the formation of NETs in response

to a bacterial infection in vitro are being established So far human blood-derived neutrophils were

stimulated with 25nM Phorbol myristate acetate (PMA) for 4 hours to stimulate NETs production and

were visualized using 4prime6-Diamidin-2-phenylindol (DAPI) to stain DNA a primary anti-H2A-H2B-DNA

complex antibody and a secondary Alexa 488-labeled antibody Our initial results could confirm that

the direct exposure of neutrophils to GAS is sufficient to trigger NETs formation In the next step

immunofluorescence microscopy will be used to reveal the entrapment of fluorescein isothiocyanate

(FITC)-labeled GAS within NETs Furthermore NETs will be quantified via a spectrofluorometric

method measuring the amount of extracellular DNA in NETs Ongoing efforts aim to study GAS-NETs

interaction and the role of different virulence factors in NETs formation or degradation

Metabolic characterization of Methylobacterium extorquens AM1 on acetate

KSchneider1 R Peyraud1 P Kiefer1 P Christen1 N Delmotte1 S Massou2 JC Portais2 J

A Vorholt1

1Institute of Microbiology ETH Zurich 8093 Zurich Switzerland

2INSA University Paul Sabatier Toulouse France

kathrinschneidermicrobiolethzch Growth in the presence of one- and two-carbon substrates requires the ability of cells to build biomass via acetyl-CoA assimilation Here we analyzed the central metabolism upon growth on acetate of the facultative methylotroph Methylobacterium extorquens AM1 which lacks the key enzyme of the glyoxylate cycle isocitrate lyase The model organism has so far been extensively studied under methylotrophic conditions ie methanol The protein repertoire of M

extorquens AM1 grown on acetate similar to growth on methanol was found to harbor the key enzymes of the serine cycle the citric acid (TCA) cycle and the ethylmalonyl-CoA (EMC) pathway Dynamic labeling experiments indicated the presence of two distinct entry points of acetate the EMC pathway and the TCA cycle Oxidation of acetate was demonstrated to occur predominantly via the TCA cycle Furthermore it was shown that glyoxylate is converted to malate and subsequently to phosphoglycerate by a reaction sequence reversed to the serine cycle and taken for formation of glycine by serine cycle serine glyoxylate aminotransferase The amino acid was used directly for biosynthesis and for the production of essential one-carbon compounds and flux through serine hydroxymethyl transferase was low relative to the operation of this key enzyme of the serine cycle upon methanol growth The results obtained in this study reveal utilization of common pathways upon growth of M extorquens AM1 on C1- and C2-compounds but major flux re-direction of the central metabolism

Maturation of DCs via inflammatory mediators results in aberrant CD8+ T cell priming

Wolfgang Kratky Annette Oxenius and Roman Spoumlrri

ETH Zuumlrich Institute for Microbiology Wolfgang Pauli-Strasse 10 8093 Zuumlrich Switzerland

wolfgangkratkymicrobiolethzch

Successful priming of adaptive immune responses is crucially dependent on innate

activation signals that convert resting antigen-presenting cells (APCs) into immunogenic

ones APCs expressing the relevant innate pattern recognition receptors (PRRs) can be

directly activated by pathogen-associated molecular patterns (PAMPs) to become competent

to prime T cells responses Alternatively it has been suggested that APCs could be

activated indirectly by pro-inflammatory mediators synthesized by PAMP-exposed cells

However data on CD4+ T cells suggest that inflammatory signals often cannot substitute for

direct pattern recognition in APC activation for the priming of T helper responses To test

whether the same is true for priming of CD8+ T cells we studied CTL development in vitro

and in mixed chimeric mice where coexisting APCs can either present a pre-processed

model antigen or directly recognize a given PAMP but not both We show that indirectly-

activated APCs promote antigen-specific proliferation of naive CD8+ T cells but fail to

support their survival and CTL differentiation Furthermore CD8+ T cells primed by indirectly-

activated APC are unable to reject tumors Thus inflammation cannot substitute for direct

recognition of PAMPs in CD8+ T cell priming These findings have important practical

implications for vaccine design indicating that adjuvants must be judiciously chosen to

trigger the relevant PRRs in APCs

Immune Control of MCMV in the Salivary Gland

Jenny Thom Annette Oxenius

ETH Zuumlrich - Institute of Microbiology

Wolfgang-Pauli-Strasse 10

CH-8093 Zuumlrich

Jennythommicrobiolethzch

Cytomegaloviruses (CMVs) are ubiquitous β-herpesviruses that establish lifelong infection

and latency in many organs Prolonged secretion of virus in saliva represents a major route

of CMV transmission with acinar glandular epithelial cells propagating virus for months after

virus replication is controlled in all other organs While CD8 T cells are sufficient to control

viral replication in visceral organs they fail to do so in the salivary gland where virus is

eventually controlled by IFNg producing CD4 T cells Using murine CMV (MCMV) our group

recently showed that despite MCMV-specific CD8 T cells being recruited to the salivary

gland their local activation is prevented as MCMV encoded immune evasion genes impair

MHC I expression on infected acinar glandular epithelial cells Moreover our data indicate

that CD4 T cells in the salivary gland are activated by non-infected antigen presenting cells

(APCs) which present internalized antigen via MHC II but are unable to cross-present on

MHC I thus failing to activate CD8 T cells My aim is to further analyze the mechanisms

leading to CD4 T cell mediated control of lytic viral replication in the salivary gland To this

end I will characterize APCs in the salivary gland phenotypically and functionally comparing

their ability to cross-present with APCs derived from lymphoid tissue and from other

secretory organs Additionally in vivo microscopy using fluorescently labeled MCMV-specific

TCR transgenic cells and a GFP labeled MCMV strain which is unable to downregulate MHC

I will shed light on the role of viral immune evasion genes in setting up the unique resistance

towards CD8 T cell mediated viral clearance in the salivary gland

A METAPROTEOMICS APPROACH TO STUDY HOST-PATHOGEN INTERACTIONS

BETWEEN PSEUDOMONAS AERUGINOSA AND CAENORHABDITIS ELEGANS

J Toller B Roschitzki C Fortes M Givskov L Eberl and K Riedel

Institute of Plant Biology Department of Microbiology University of Zurich jtolleraccessuzhch

Functional Genomics Center Zuumlrich ETH UZH Department of International Health Immunology and Microbiology University of

Copenhagen Institute of Microbiology Department of Microbial Proteomics TU Braunschweig

Pseudomonas aeruginosa a Gram-negative opportunistic pathogen causes life-threatening

and chronic infections in immunocompromised patients and employs an N-acyl homoserine

lactone-mediated quorum sensing (QS) system to coordinate eg the expression of virulence

factors in a cell-density dependent manner Non-mammalian infection models like

Caenorhabditis elegans are well-established tools to obtain first insights into molecular

mechanisms underlying bacterial pathogenicity State-of-the-art gel-free semi-quantitative

proteomics allows investigating the ldquoinfectiosomerdquo defined as global changes in protein

expression in both the host and the pathogen during the infectious-like process (ILP)

Here we present a comparative proteome analysis of the highly pathogenic P

aeruginosa strain UCBPP-14 during colonization of C elegans and growth on NGMII-agar

(control) respectively To this end the nematodes were homogenized after 24h of ldquoinfectionrdquo

proteins were extracted and trypsin-digested The resulting mixture of bacterial and

nematode-derived peptides was analyzed by reverse-phase liquid chromatography coupled

to electrospray ionization tandem mass spectrometry (MS) A total of 3940 C elegans and

1500 P aeruginosa proteins were identified from the ldquoinfectedrdquo nematode while 2952

bacterial proteins were found in the control Numerous QS-regulated proteins like proteins

involved in phenazine biosynthesis or iron sequestration were found to be highly expressed

during the ILP Overall these findings strikingly confirm the central role of QS-regulated

protein expression for P aeruginosa pathogenicity

The obtained data are currently validated by testing P aeruginosa mutants defective

in selected proteins upregulated during the ILP in the C elegans pathogenicity model We

are planning to extend our metaproteome analyses to a chronic murine infection model

system

Analysis of SopE-dependent Salmonella Typhimurium invasion into HeLa cells

Saskia Kreibich Mario Emmenlauer Pauli Raumlmouml Jason Mercer Peter Horvath Wolf-Dietrich Hardt

Institute of Microbiology Wolfgang-Pauli-Str10 8093 Zurich

saskiakreibichmicrobiolethzch

Salmonella Typhimurium (S Tm) is a common cause of gastroenteritis in humans leading to

more than 3 million deaths per year To enable the invasion into intestinal epithelial cells S

Tm comprises two type III secretion systems (TTSS) which translocate different effector

proteins into the host cell SopE is one of the main effectors that induces the entry into

epithelial cells by acting on Rho GTPases which trigger the formation of actin-containing

membrane protrusions (ldquomembrane rufflesrdquo)

Since the complex network of interactions between SopE and host cell factors leading to a

successful invasion is still not entirely understood we aim to perform a genome-wide RNAi

screen as part of the InfectX consortium in order to identify the missing gaps and

interconnections of required host cell factors We began by establishing a standardized

transfection protocol Then we performed a ldquokinome screenrdquo including all 715 encoded

human kinases in triplicates This verified a good reproducibility of the screening assay

revealed first potential candidates for further analysis and allowed first side by side

comparisons of the host factor requirements of different bacterial and viral pathogens Most

importantly this has set the step for the genome-wide screen The outcome of the whole-

genome RNAi screen will help to understand the S Tm infection process in a

comprehensive manner Furthermore the comparison of screens involving these diverse

pathogens will reveal the differences and similarities of their required host cell factors being

very valuable concerning the development of new drugs that interfere with the pathogenrsquos

entry into human cells

INFLUENCE OF ACIDITY ON THE ABUNDANCE AND DIVERSITY OF SOIL BURKHOLDERIA POPULATIONS

N Stopnišek1 N Fierer2 B Frey3 L Eberl1 L Weisskopf1 1Institute of Plant Biology University of Zurich Zurich Switzerland 2Department of Ecology and

Evolutionary Biology University of Colorado at Boulder Boulder CO USA 3Swiss Federal Institute for Forest Snow and Landscape Research WSL Birmensdorf Switzerland

Recent studies have shown that pH plays a major role in the biogeography of micro-organisms However the mechanisms that enable specific taxa to establish in low pH environments while others are excluded have not yet been investigated In this project we assess this question using Burkholderia as a model genus The goals of this research are i) to evaluate the role of low pH tolerance in the biogeography of the genus Burkholderia and ii) to assess the species-specificity of the low pH tolerance In order to investigate the effect of pH tolerance on the biogeographical distribution of Burkholderia species relative Burkholderia abundance (qPCR on 16S rRNA) and diversity (clone libraries of the 16S rRNA and recA genes) will be analyzed in an intercontinental collection of soil samples (Fierer and Jackson 2006) In addition the acid tolerance will be tested in vitro in isolated Burkholderia strains First results indicate that i) Burkholderia species are more abundant in neutral to low pH soils than in high pH soils independent of geographical location ii) the absence from higher pH soils is not due to an intrinsic incapacity of Burkholderia species to tolerate high pH values and iii) low pH tolerance as tested in in vitro physiological studies with isolated strains grown in LB with different pH values is a general feature of the Burkholderia genus The highest growth was observed in moderately acidic conditions (pH 45-5)

Do altered natural killer cell responses to primary Epstein-Barr virus infection predispose for infectious mononucleosis Tarik Azzi Christian Muumlnz David Nadal University Childrens Hospital UZH Experimental Infectious Diseases August-Forel-Strasse 1 CH-8008 Zurich tarikazzikispiuzhch Primary infection with the Epstein-Barr virus (EBV) a human gamma-herpesvirus that infects more than 95 of the world population and is associated with cancer and autoimmune diseases runs an unspecific or asymptomatic course in young children After the age of 5 years however primary infection with EBV may elicit infectious mononucleosis (IM) an exaggerated immune response to the virus clinically characterized by fever tonsillitis and enlargement of lymph nodes liver and spleen Although IM resolves spontaneously it is thought to increase the risk for EBV-associated cancer or autoimmunity specifically Hodgkinrsquos lymphoma or multiple sclerosis Why IM develops is unknown We hypothesize that the high EBV levels observed during IM could be caused by inefficient innate immunity to the virus mediated by natural killer (NK) cells Thus we propose to investigate NK cell responses at various ages as well as during IM and to which extent inefficient NK cell responses might predispose for it An improved understanding of age-dependent NK cells function and responses may contribute to increased knowledge on the pathogenesis of EBV-associated diseases and thus provide potential targets for their prevention and treatment

Poster_AllAbstracts_22_08_2011_08_58_24

Dear Students

Best wishes

Contact information

Josh Crouse +41 78 7250838

Heike Nowag +41 78 6273403

Sunday

Monday

Tuesday

Dietmar Zehn

Naseem Malik

Damaris Wyss

Martin Ackermann

Assistant Professor

ETHEawag

Talk No Name

Stress Response

McCallum

vdenglerimmuzhch

understood

AlineTaveirauszch

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

Dear Students

Best wishes

Contact information

Josh Crouse +41 78 7250838

Heike Nowag +41 78 6273403

Sunday

Monday

Tuesday

Dietmar Zehn

Naseem Malik

Damaris Wyss

Martin Ackermann

Assistant Professor

ETHEawag

Talk No Name

Stress Response

McCallum

vdenglerimmuzhch

understood

AlineTaveirauszch

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

Contact information

Josh Crouse +41 78 7250838

Heike Nowag +41 78 6273403

Sunday

Monday

Tuesday

Dietmar Zehn

Naseem Malik

Damaris Wyss

Martin Ackermann

Assistant Professor

ETHEawag

Talk No Name

Stress Response

McCallum

vdenglerimmuzhch

understood

AlineTaveirauszch

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

Sunday

Monday

Tuesday

Dietmar Zehn

Naseem Malik

Damaris Wyss

Martin Ackermann

Assistant Professor

ETHEawag

Talk No Name

Stress Response

McCallum

vdenglerimmuzhch

understood

AlineTaveirauszch

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

Dietmar Zehn

Naseem Malik

Damaris Wyss

Martin Ackermann

Assistant Professor

ETHEawag

Talk No Name

Stress Response

McCallum

vdenglerimmuzhch

understood

AlineTaveirauszch

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

Assistant Professor

ETHEawag

Talk No Name

Stress Response

McCallum

vdenglerimmuzhch

understood

AlineTaveirauszch

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

ETHEawag

Talk No Name

Stress Response

McCallum

vdenglerimmuzhch

understood

AlineTaveirauszch

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

ETHEawag

Talk No Name

Stress Response

McCallum

vdenglerimmuzhch

understood

AlineTaveirauszch

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

ETHEawag

Talk No Name

Stress Response

McCallum

vdenglerimmuzhch

understood

AlineTaveirauszch

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

Talk No Name

Stress Response

McCallum

vdenglerimmuzhch

understood

AlineTaveirauszch

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

Stress Response

McCallum

vdenglerimmuzhch

understood

AlineTaveirauszch

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

understood

AlineTaveirauszch

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

understood

AlineTaveirauszch

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

understood

AlineTaveirauszch

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

understood

AlineTaveirauszch

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

understood

AlineTaveirauszch

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

understood

AlineTaveirauszch

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

understood

AlineTaveirauszch

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

understood

AlineTaveirauszch

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

AlineTaveirauszch

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

AlineTaveirauszch

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

IsaakQuastuzhch

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

Poster No Name

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

CH-8008 Zuumlrich

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

EFFECTOR CELLS

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

CH-8057 Zuumlrich

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

Abstract

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

from the MTS

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

immunopathology

downregulation

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

Switzerland

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

cytokines

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

receptor antibody

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

Epstein-Barr virus

Tel +41-44-6348834

Abstract

A Vorholt1

CH-8093 Zuumlrich

system

A Vorholt1

CH-8093 Zuumlrich

system

A Vorholt1

CH-8093 Zuumlrich

system

A Vorholt1

CH-8093 Zuumlrich

system

CH-8093 Zuumlrich

system

CH-8093 Zuumlrich

system

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