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HMIHost-MicrobeInteractomics
The dynamic interplay between microbiota and host during 1 month of conventionalisation of germ-free mice
Peter van Baarlen 25 September 2012 / MetagenomicsHost-Microbe Interactomics Group Wageningen University
E-mail:[email protected]
HMIHost-MicrobeInteractomics
Focus on gut mucosal interactions between bacteria and their hosts We study pathogenic as well as commensal (symbiotic) bacteria including
the microbiota of the oral cavity, esophagus and intestinal tract We study cellular processes in epithelial cell lines and in mucosal tissues of
human, pig and mouse, and zebrafish The HMI research is multidisciplinary: cell biology, immunology, molecular
(micro-)biology, -omics and diverse microscopy
Research within the HMI group
HMIHost-MicrobeInteractomics
(Confocal) microscopy (Immuno)histochemistry Cell culture of in vitro gut and tracheal epithelial cell lines (human and pig) Immune cell analysis (flow cytometry) Toll-like receptor (TLR) signal transduction assays Transfection of cell lines using Lentivirus to study gene expression
responses (including knock-down) to bioactive molecules and bacteria Infection models to study pathogens Molecular (micro)biology High-content HTP automated microscopy (BD Pathway platform) Cellular pathway reconstruction: visualisation, integration and analysis in
(functional) -omics Microbiota and microbiome analysis Clustering and stratification of individuals
Techniques used at HMI
HMIHost-MicrobeInteractomics
the number of bacterial species in the intestine is larger than 1000
Gut bacteria produce factors that “train” our immune system and are essential for intestinal (immune) homeostasis
Presence of gut bacteria is necessary for proper intestinal development (nutrient resorbtion, immunity, ...)
Dysbalanced intestinal colonisation may lead to improper immune responses that can lead to immune, metabolic and auto-immune diseases
Only 20-30% of gut bacteria has ever been cultured
Why study the intestine? The intestine: one large microbial ecosystem
HMIHost-MicrobeInteractomics
How to study effect of changes in microbiota on the host?o preferably, trace in
neonateso monitor changes in
microbiota diversity "at relevant stages"
o monitor corresponding host responses
Simplified model: Germ-free and gnotobiotic miceo well-studied modelo amenable to experimentingo possible to sample
microbiota and organs
The microbiota have a huge impact on human health throughout life
HMIHost-MicrobeInteractomics
Gnotobiotic animals - not only of this millennium
HMIHost-MicrobeInteractomics
compartmentalisation involves:o immune cellso metabolism: dietary
nutrientso microbiota (anaerobic
metabolism)
Experimental set-up: sample multiple regions throughout the guto jejunum o ileumo colon
Compartmentalisation of the animal intestine and microbiota
Carmody and Turnbaugh, CHM 2012
HMIHost-MicrobeInteractomics
Time-series analysis of GF mouse colonisation by microbiota
+ =
Michiel Kleerebezem, Microbiology WUJerry Wells, HMI WUJoël Doré, INRASahar El-Aidy, Microbiology WU
HMIHost-MicrobeInteractomics
Host model: germ-free mice (Joël Doré), mouse microbiota
D0 D2D1 D4 D8 D16
GF days colonisation by bacteria
sampling 3 intestinal regions: jejunum, ileum, & colonHistochemistryTranscriptomicsMetabolomics (urine & blood samples;collaboration with J. Nicholson lab)
GF: -♂ C57 BL/6 J, 8-10 weeks old- 6 mice/ day (D)- Diet: standard chow (sterilised)
HMIHost-MicrobeInteractomics
Mouse intestinal colonisation: immunity meets metabolism
how are these transcriptomechanges coordinated across time?
HMIHost-MicrobeInteractomics
Gene clusters that form time- or location-dependent modules
HMIHost-MicrobeInteractomics
Enriched GO categories during mouse colonisation by microbiota
calculated global enriched GO gene sets and their up-downregulation
gene sets were further evaluated by network analysis
calculated global enriched GO gene sets and their up-downregulation
gene sets were further evaluated by network analysis
HMIHost-MicrobeInteractomics
Annotating gene co-expression modules using gene ontologies
HMIHost-MicrobeInteractomics
MITchip: phylogenetic arrayo 3.580 probes (detecting
OTUs)o Agilent platform (standard
feature extraction and data analysis)
MITchip: variant of HITchip (Rajilic-Stojanovic et al. Env. Microbiol. 2009)o good (>0.93) correlation
between HItchip and 454 pyrosequencing at phylum, class, and order level
o lower (0.77) correlation at family and variable at genus level
Analysis of mouse intestinal microbiota via MITchip analysis
HMIHost-MicrobeInteractomics
Microbiota clustering across days
HMIHost-MicrobeInteractomics
Microbiota diversity changes at different rates across GI regions
HMIHost-MicrobeInteractomics
1 2 4 8 160
500000
1000000
1500000
2000000
2500000
3000000
3500000
4000000
4500000
5000000Colon
Colonisation (days)
Prob
e in
tens
ityBacilli Bacteroidetes Clostridium cluster IV Clostridium cluster IX Clostridium cluster XIVa Proteobacteria
Jejunum
Colonisation (days)1 2 4
Prob
e in
tens
ity
0
100000
200000
300000
400000
500000
600000
700000
800000
900000
8
Dynamics of microbiota - abundance of specific taxa
Development of microbiota diversity starts between Day 2 & 4 in the jejunum Development of microbiota diversity starts between Day 4 & 8 in the colon
HMIHost-MicrobeInteractomics
Jejunum: composition of microbiota diversity shows expansions of specific taxa
Colon: Similar diversity across timepoints, dominated by Clostridia XIVa and Bacteroidetes
1J 2J 4J 8J 16J
Jejunum Colon
0%
20%
40%
60%
80%
100%
Clostridia XIVa
Bacteroidetes
Clostridia IV
Proteobacteria
Bacilli
Clostridia I, II
1C 2C 4C 8C 16C
Dynamics of microbiota - relative abundance
HMIHost-MicrobeInteractomics
Gross changes in Firmicutes populations across time in colono loss of Bacilli, increase of
Clostridia
largest effect on variation: SI vs colono total diversity of microbial
taxa in SI lowero jejunum appears to have a
lower diversity than ileumo biological cause?
Microbiota per intestinal region differ substantially
PC1-% variance explained (40.2%)
HMIHost-MicrobeInteractomics
PCA of taxa strongly changing in abundance in MITchip analysis
colon
HMIHost-MicrobeInteractomics
Firmicutes decrease slightly, Bacteroidetes increaseo Firmicutes: largest proportion of jejunal microbiota
at day 1o all Bacteroidetes taxa increase similarly to 40% of
final microbiomeo jejunal communities are distinct from those in ileum
and colon
Jejunal communities are less diverse and present from day 1
HMIHost-MicrobeInteractomics
Days 1-2o Proteobacteria increaseo Bacteroidetes increaseo Lactobacilli, Enterococci decrease
Day 4o Sphingomonas decreaseo Helicobacter decreaseo Desulfovibrio decrease
Days 8-16-30o Firmicutes dominateo Bacteroidetes decrease
Loss of typical (pathobiont) genera at day 4 in jejunum
HMIHost-MicrobeInteractomics
Day 4 marks transition during which immunity is strongly stimulated
HMIHost-MicrobeInteractomics
increased sialylation of mucins at day 4o increases adhesion between epithelial
cells
increased emptying of mucins by goblet cells in jejunum and colon
strong induction of interferon-gamma at day 4o IFN-gamma: critical cell signalling
protein that is essential for innate and adaptive immunity
Changes in numbers of specific microbial taxa at day 4 in jejunum appears to be a result of a stronger immune response
Strong induction of innate immunity at day 4
HMIHost-MicrobeInteractomics
Mouse metabolomics has shown great promise in earlier studies
Claus et al. MSB 2008
HMIHost-MicrobeInteractomics
Challenges in studying metabolomes - complexity vs. knowledge
HMIHost-MicrobeInteractomics
1H-NMR spectroscopyo Fourier transformationo spectra calibrated to lactate
Statistics via linear (un)supervised partial least squares models in Matlabo O-PLS models to identify
differentially accumulating metabolites
o O2-PLS models to integrate metabolome and transcriptome data
Metabolic profiling in lumen, urine, blood and tissues
In collaborations with Nicholson Lab, UK and NMC (Leiden)
HMIHost-MicrobeInteractomics
significant changes in plasma metabolite concentrations at day 4o ky/trp ratio: exemplifies trp degradation
via ky pathway via Ido; hallmark of actively growing (immune) cells
o citrullin/L-glutamine ratio: L-glut can be converted to citrulline, a precursor of arginine and NO (a.o. via Nos2/iNos) that are involved in enhanced macrophage activity
microbiota composition and tissue transcriptomes correlate with systemic (blood) metaboliteso changes in microbiota correlate with
increased immune activationo changes in microbiota correlated with
changes of important blood plasma metabolites
Plasma accumulation of metabolites at day 4 correlate with -omes
HMIHost-MicrobeInteractomics
significant changes in plasma inflammation-associated cytokine concentrations at day 4o cytokines measured via Luminex
mouse MAP multiplex immunoassay (left panel)
intestinal gene expression correlates with plasma cytokine concentrationso corresponding gene expression
measured via QPCR in individual mice
Day4 plasma immune cell cytokines correlate with plasma metabolites
HMIHost-MicrobeInteractomics
Exploring correlations between transcriptomes and metabolomes
jejunum
HMIHost-MicrobeInteractomics
Correlations between microbiota taxa and host metabolic pathways
HMIHost-MicrobeInteractomics
Changes in microbiota composition impact on jejunal metabolism
HMIHost-MicrobeInteractomics
Major microbiota-induced colon metabolomic changes during conv.
HMIHost-MicrobeInteractomics
Microbiota-induced changes in host immune system during conv.
HMIHost-MicrobeInteractomics
Integrating -omics, microbiota changes and histology
HMIHost-MicrobeInteractomics
Acknowledgements
Wageningen UniversityMichiel KleerebezemJerry WellsSahar El AidyMuriel DerrienNMC
RU Groningen MCBert GroenDirk-Jan Reijngoud
Imperial College, UKElaine HolmesJeremy NicholsonSandrine ClausClaire Merrifield