title: Immunoregulation by the gut microbiota.
abstract: The human intestinal mucosa is constantly exposed to commensal microbiota. Since the gut microbiota is beneficial to the host, hosts have evolved intestine-specific immune systems to co-exist with the microbiota. On the other hand, the intestinal microbiota actively regulates the host's immune system, and recent studies have revealed that specific commensal bacterial species induce the accumulation of specific immune cell populations. For instance, segmented filamentous bacteria and Clostridium species belonging to clusters XIVa and IV induce the accumulation of Th17 cells in the small intestine and Foxp3(+) regulatory T cells in the large intestine, respectively. The immune cells induced by the gut microbiota likely contribute to intestinal homeostasis and influence systemic immunity in the host.
authors.affiliation: Department of Immunology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan.
authors.forename: Junko
authors.initials: J
authors.lastname: Nishio
authors.forename: Kenya
authors.initials: K
authors.lastname: Honda
mesh_terms: D000818:Animals; D001419:Bacteria / Q000276:immunology*; D003013:Clostridium / Q000235:genetics / Q000378:metabolism; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism; D051858:Forkhead Transcription Factors / Q000378:metabolism; D006801:Humans; D007070:Immunoglobulin A / Q000378:metabolism; D020381:Interleukin-17 / Q000378:metabolism; D007413:Intestinal Mucosa / Q000276:immunology / Q000382:microbiology; D007422:Intestines / Q000276:immunology* / Q000382:microbiology*; D054892:Metagenome; D050378:T-Lymphocytes, Regulatory / Q000276:immunology / Q000378:metabolism; D058504:Th17 Cells / Q000276:immunology / Q000378:metabolism
chemical_list: C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D007070:Immunoglobulin A; D020381:Interleukin-17