KIR2DL3 and KIR3DL1. Thus, differential expression of KIR mayaffect NK cells function contributing with chronicity in HCVinfection. Supported by FONACIT G-2005000395.

doi:10.1016/j.clim.2008.03.383

Su.33. Production of TNF-α and IL-12 by PeripheralBlood Mononuclear Lymphocytes from Patients withHerpes Virus Infections Reflects the Intensity ofClinical SymptomsGeorge Drannik,1 V. Fesenkova,2 M. Derkach,2

A. Kurchenko,1 Lawrence DuBuske.3 1National MedicalUniversity, Kiev, Ukraine; 2Institute of Urology, Kiev,Ukraine; 3Immunology Research Institute of New England,Gardner, MA

Introduction: IL-12 and TNF-α produced by peripheralblood mononuclear cells may show a differential patternof synthesis in patients having various manifestations ofherpes virus infections. Methods: Two groups of patientshaving herpetic infections were examined: Group I con-sisted of 15 patients who had herpetic symptoms whichoccurred less than 5 times a year; Group II consisted of 20patients had herpetic symptoms more than 7 times a year.Mononuclear cells obtained from these patients wereisolated using a velocity sedimentation gradient (1.076-1.078), and were cultured in RPMI-1640 containing 10%fetal calf serum, 40 mg/ml gentamycin, 5 × 10 M-2mercaptoethanol and 3% L-glutamine. The cells weresuspended at 1.5×10 6 cells/ml and incubated for 24 h ina CO2-incubator at 370 C either with or without PGA10 mg/ml. Cytokine contents from cell supernatants wereassessed by an immunoenzyme method (Diaclone, USA) forIL-12 (p40-70) and TNF-α, which were detected employingthe immunoenzyme analyzer Stat Fax-303 Plus. Results:Group I had spontaneous production of IL-12 which was11.2±1.02 pg/ml, with mitogen inducing 15.3±1.06 pg/ml. Group II had spontaneous IL-12 production which was8.6±0.62 pg/ml, with mitogen inducing 10.4±0.78 pg/ml.Group I had spontaneous production of TNF-α of 43.2±4.2 pg/ml, with mitogen inducing a 1.4 fold greater level incomparison with spontaneous production. Group II hadspontaneous TNF-α production of 74.8±1.1 pg/ml, withmitogen inducing 90.2±1.0 pg/ml. Conclusions: In patientshaving frequent clinical manifestations of herpes virusinfection there was reduced spontaneous and induced IL-12production and increased production of TNF-α in compar-ison with patients with less frequent clinical herpeticsymptoms.

doi:10.1016/j.clim.2008.03.384

Su.34. Elevated Levels of Serum Antibody AgainstH. Pylori in New Zealand Black MiceMing-han Wu,1 Yi-Chun Cho,2 Ya-Ken Chen,2 Wei-Kung Wu,2

Chia-rui Shen,2 Chao-Lin Liu.1 1Min Chi University ofTechnology, Taishan, Taiwan; 2Chang Gung University,Kweishan, Taiwan

Either cross-reactivity or molecular mimicry betweenenvironmental and autoantigens has been proposed as amechanism underlying spontaneous autoimmune disease.Such cross-reactivity may provide increased levels ofparticular antigenic sequences or greater avidity ofrecognition to overcome self-tolerance. Similarly, in thecase of mimicry by infectious agents and innate stimulimay enhance the specific immunogenicity. New ZealandBlack (NZB) mice spontaneously develop autoimmunehemolytic anemia (AIHA). In previous studies, we haveshown that the major target of the pathogenic RBCautoantibodies is Band 3 and that CD4+ T-cells isolatedfrom NZB mice respond to this autoantigen. A Band 3peptide, which contains the predominant sequence 862-870recognized by NZB T cells bears a helper epitope able tomodulate the AIHA in vivo. Therefore, the aim of currentwork is to determine the possibility that the cross-reactivestimulus initiates responses to Band 3. First, we haveexplored that NZB anti-RBC autoantibodies had cross-reactivity with H. Pylori as it contains a peptide sequencehaving a very high degree of homology with the Band 3peptide 862-870. Indeed, higher titers of antibodies againstH. Pylori found in the NZB mice were correlated with moreRBC autoantibodies found in the same mice. In fact, ourpresent study show that the production of RBC autoanti-bodies and the death rate could be enhanced afterimmunizing NZB mice intraperitoneally with the shortpeptide of H. Pylori. What is more, high levels of the co-stimulatory/active molecules-CD86 were found in their Bcells. Taken together, the current observations indicate H.Pylori or other microbial cross-reactivity may play animportant role underlying autoimmune hemolytic anemia.

doi:10.1016/j.clim.2008.03.385

Su.35. Epstein-Barr Virus Downregulates B CellSurface CD1d to Evade Natural Killer T CellDetectionBrian Chung,1 Lenka Allan,2 Dong Jun Zheng,2 JohnPriatel,2 Peter van den Elzen,3 Rusung Tan.3 1Universityof British Columbia, Vancouver, BC, Canada; 2Child andFamily Research Institute, Vancouver, BC, Canada; 3BCChildren's Hospital, Vancouver, BC, Canada

Epstein-Barr virus (EBV) is a ubiquitous oncogenicherpesvirus that infects and persists lifelong in human Bcells. In the majority of healthy individuals, EBVinfection is asymptomatic or causes minor illness,although a small proportion of individuals developinfectious mononucleosis for reasons not fully under-stood. Individuals with primary or acquired immunode-ficiencies frequently develop severe lymphoproliferativedisorders associated with EBV highlighting the impor-tance of controlling EBV replication and B cell transfor-mation. Cytotoxic T lymphocytes (CTL) and natural killer(NK) cells are thought to be the major immune subsetsthat limit EBV infection. Interestingly however, indivi-duals lacking NKT cells such as those with X-linkedlymphoproliferative disease (XLP), suffer from fatallymphoproliferative disorders following acute EBV

S135Abstracts

infection. Therefore, we hypothesize that natural killerT (NKT) cells also play a critical role in regulating EBVinfection. We observed that nascent EBV-infected per-ipheral blood B cells, tonsillar B cells and long-term EBV-transformed lymphoblast cell lines downregulate thesurface expression of CD1d, the MHC class I-like moleculeresponsible for presenting antigens to NKT cells. Incontrast, EBV infected MHC class I and class II surface Bcell expression was unchanged suggesting EBV maydecrease surface CD1d expression to specifically evadeNKT cell detection. Compared to uninfected B cells, EBV-infected B cells pulsed with the NKT cell agonist α-galactosylceramide failed to stimulate CD1d-restricted Tcell cytokine production by NKT cell lines. Takentogether, our data suggest that NKT cells may regulateEBV-infected B cells and that an absence of NKT cellsresults in an inability to control viral replication andvirus-induced transformation.

doi:10.1016/j.clim.2008.03.386

Su.36. ImmunizationofNeonates: GreaterProtection,Stronger Primary and Secondary Immune Responseand a Unique Memory T Cell ProfileBrian Reikie,2 Kinga Smolen,2 Daniela Loeffler,1 DarrenBlimkie,1 Tobias Kollmann.1 1University of BritishColumbia, Vancouver, BC, Canada; 2University of BritishColumbia, Vancouver, BC, Canada

Approximately 2.5 million neonates and infants dieannually from infection marking this as the time of lifemost burdened by infectious disease. Prevention ofneonatal mortality is hampered by a lack of safe andeffective vaccines. However, rational vaccine designnecessitates an understanding of neonatal immune regula-tion. In order to better understand neonatal immunememory development in response to vaccination we usedthe model vaccine Listeria monocytogenes expressingovalbumin (Lm-Ova) in newborn mice. Our results indicatethat neonates mount stronger interferon gamma (IFNγ)responses to a broader array of vaccine antigens upon re-exposure to the cognate vaccine pathogen, and that bothprotection and IFNγ responses are induced with lowerinitial vaccination dose. The primary immune response tovaccination was also examined and neonatal T cellsexhibited stronger IFNγ expression, equivalent interleukin2 (IL-2) production, and an impaired ability to producecentral memory T cells (Tcm) when compared to adults.Neonates vaccinated with LM-Ova induced a T cell responsedominated by effector memory T cells (Tem), whichprovides a potential explanation for the greater levels ofprotection observed against virulent Listeria. Increasingvaccine dose induced decreasing Tcm production in adults,whereas neonates produced only Tem. This supports ournotion that the neonatal immune system provides a uniqueand at times potentially superior immunological milieu forinduction of protective immune responses by vaccination.

doi:10.1016/j.clim.2008.03.387

Su.37. Immune Response to Rotavirus in thePathogenesis of Celiac Disease: Molecular Effects ofa Subset of Anti-VP7 Viral Protein Antibodies onIntestinal Epithelial Cells using a GeneArray ApproachAntonio Puccetti,1 Marzia Dolcino,1 Giovanna Zanoni,2

Claudio Lunardi. 3 1Istitute G. Gaslini, Genova, Italy;2University of Verona, Verona, Italy; 3University of Verona,Verona, Italy

Celiac disease (CD) is sustained by an inappropriateimmune response against gluten in genetically susceptibleindividuals. In addition to genetic and dietary factors,rotavirus infection has been implicated in CD pathogenesis.We have recently demonstrated that sera of patients withactive CD specifically recognize a peptide sharing homologywith the VP-7 rotavirus protein and with self-antigens. Thisstudy aimed at evaluating the fine molecular effects inducedby the anti-viral peptide antibodies in intestinal epithelialcells. Specific antibodies against the viral-derived VP7peptide have been affinity purified from sera of patientswith active CD. The effect of these antibodies cross-reactingwith self antigens on T84 intestinal cells has been analyzedwith the gene array technique. Modulated genes have beenidentified by at least 2-fold change in expression. Theanalysis has been validated by quantitative PCR. Thedifferent gene expression patterns were analyzed using theArray Assist ™ software (Stratagene, La Jolla, California,United States) and a functional clusterization was alsoperformed. Exposure of T84 cells to anti-VP7 peptide-specific antibodies resulted in the upregulation of 697transcripts. Several gene clusters were upregulated includ-ing genes encoding for chemokines and for moleculesinvolved in inflammation and immune response processesas well as in apoptosis and in regulation of cell proliferation.These data demonstrate that intestinal epithelial cellsexposed to antibodies directed against the rotavirus derivedVP7 peptide modulate clusters of genes similar to thosemodulated during CD. These results further confirm theimportant role played by rotavirus infection in the pathogen-esis of CD.

doi:10.1016/j.clim.2008.03.388

Su.38. Attenuated Salmonella Typhi Vaccine StrainCVD 908-htrA Used as a Live Vector ExpressingFull-length Anthrax Protective Antigen in aHeterologous Prime-boost RegimenChinchilla Magaly, Marcela Pasetti, Jin Wang, Seema Thayil,Ivonne Arciniega-Martinez, Aldo Rossini, Myron Levine,James Galen. University of Maryland, Baltimore, MD

We hypothesize that mucosal administration of attenu-ated Salmonella enterica serovar Typhi live vectors expres-sing full-length Protective Antigen (PA83) from Bacillusanthracis, can prime the immune system to generate longlasting immune responses. We investigated the primingcapacity of S. Typhi strain CVD 908-htrA, expressing a proteinfusion of PA83 fused to the S. Typhi export protein ClyA, toprime the immune system of non-human primates and mount

S136 Abstracts