The love-hate relationship between bacterial polysaccharides and the host immune system.
This article explores the fascinating relationship between the mammalian immune system and the bacteria that are present in the mammalian gut. Every human is an ecosystem that hosts 10(13)-10(14) bacteria. We review the evidence that immunomodulatory molecules produced by commensal bacteria in the gut have a beneficial influence on the development of certain immune responses, through eliciting the clonal expansion of CD4(+) T-cell populations. This process seems to contribute to the overall health of the host by offering protection against various diseases and might provide supporting evidence at a molecular level for the 'hygiene hypothesis' of allergic immune disorders.
Mazmanian
Sarkis K
SK
Division of Biology, California Institute of Technology, Mail code 156-29, 1200 East California Boulevard, Pasadena, California 91125, USA.
Kasper
Dennis L
DL
D000818:Animals; D000941:Antigens / Q000276:immunology; D006262:Health; D006801:Humans; D007107:Immune System / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology; D011135:Polysaccharides, Bacterial / Q000737:chemistry / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology
D000941:Antigens; D011135:Polysaccharides, Bacterial