Microbial control of regulatory and effector T cell responses in the gut - PubMed (original) (raw)

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Microbial control of regulatory and effector T cell responses in the gut

Timothy Hand et al. Curr Opin Immunol. 2010 Feb.

Abstract

The human intestine harbors and is in constant contact with 1000 trillion microbes, composed of an estimated 15,000 strains. Recent studies have changed our perspective of commensal microbes from benign but inert passengers, to active participants in the processing of food into useful metabolic components, the postnatal development of mucosal and systemic immunity, and in its long-term steady state function. Although mucosal surfaces have to constitutively integrate a multitude of microbial derived signals, new evidence suggests that defined bacteria or microbial products can play a dominant role in the induction of distinct class of immune responses. In this review we will focus on recent findings associating microbes that colonize or invade the gut, specialized mucosal DCs, and induction of effector or regulatory response in the GI tract.

Published by Elsevier Ltd.

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Figure 1

Figure 1. Conditioning of T cell by commensals

The gut is colonized by a complex microbiota composed of microbes with potential beneficial (symbionts) or pathogenic effects for their host. This site is constantly conditioned by dietary elements such as vitamin A or fiber that can regulate the homeostasis of this site via their metabolites (respectively retinoic acid (RA) or short chain fatty acid (SCFA)). In the lamina propria or Peyer’s patches, various subsets of DCs (e.g. for the lamina propria CD11c+CD103+ or CD11b+CD14+CXCR1+DC) can be found. These DCs can induce Foxp3+Treg via their capacity to metabolizing and release RA (CD103+DCs) or induce various classes of effector responses following exposure to microbial derived products (e.g. Flagellin, Bacterial DNA) or metabolites (ATP).

References

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