セッション情報 Host-microbial Interaction and Immunology in IBD a. Basic Aspects

タイトル

IF3a-3 Role of Commensal Microbiota in Intestinal Immunity and Host Defense

演者 Hiroshi Ohno(Research Center for Allergy and ImmunologyRIKENJapan)
共同演者
抄録 Inside our gut are inhabited by numerous commensal bacteriaor microbiota. The commensal microbiotawell exceed eukaryotic cells constituting the human body in number. lnteraction between the microbiotaand the host establishes the unique gut ecosystemwhich impact the host physiology and pathology invarious waysShaping the host immune system is one such example. lt has been known that the immunesystem is not fu皿y developed in gerrnfree mice. Recentlya certain species of commensal bacteria havebeen shown to be involved in the ・expansion of a subset of T lymphocytes. For examplepolysaccharide A(PSA) 一producing Bacteroides fragilis corrects Thl/Th2 balance in the spleen by stimulating expansion ofThl cells. PSA has also been reported to induce regulatory T (Treg) cells and mucosal tolerance in the in-testine. Colonic Treg cells are also promoted by other commensal bacteria such as Clostridium species. Bycontrastsegmented filamentous bacteria increase the number of Th17 cells in the intestine.On the other handthe mucosal iエnmune system is sensing and containing the commensal microbiota tomaintain the homeostasis of gut ecosystem. Collapse in this homeostasis could result in a various diseasestate including IBD. Thereforeunderstanding of the host-microbiota interaction is critical for the elucida-tion of IBD pathogenesiswhich eventually lead to the control and prevention of the disease. To tackle thisproblemwe try to establish and apply the multi-omics approachwhere data from exhaustive analysessuch as (meta)genomics(meta)transcriptomics and metabomomics are integrated. Effectiveness of ourapproach has been proven by applyin g to a gnotobiotic mice model of pathogenic Escherichia coli infec-tion. The multi-onics approach will provide a new tool to elucidate IBD pathogenesis.
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