Article

Regulation of innate and adaptive immunity by the commensal microbiota

Infectious Diseases Service, Department of Medicine, Memorial Sloan-Kettering Cancer Center, Immunology Program, Sloan-Kettering Institute, New York, NY 10065, United States.
Current opinion in immunology (Impact Factor: 7.48). 04/2011; 23(3):353-60. DOI: 10.1016/j.coi.2011.03.001
Source: PubMed

ABSTRACT

The microbial communities that inhabit the intestinal tract are essential for mammalian health. Communication between the microbiota and the host establishes and maintains immune homeostasis, enabling protective immune responses against pathogens while preventing adverse inflammatory responses to harmless commensal microbes. Specific bacteria, such as segmented filamentous bacteria, Clostridium species, and Bacteroides fragilis, are key contributors to immune homeostasis in the gut. The cellular and molecular interactions between intestinal microbes and the immune system are rapidly being elucidated. Here, we review advances in our understanding of the microbial populations that shape the mucosal immune system and create a protective defense that prevents infection while tolerating friendly commensals.

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    • "However, recolonizing germ-free mice (GF) with species-specific microbiota restored the intestinal immune compartment and reduced Salmonella fecal CFUs 4 days post infection (Chung et al., 2012). Commensal-induced Th17 cells also contribute to pathogen defense by producing IL-17 and IL-22, which promote antibody class switching in B cells, induce anti-microbial peptides and contribute to neutrophil recruitment (Jarchum and Pamer, 2011; Littman and Pamer, 2011; Maynard et al., 2012). The microbiota also sends signals to immune cells in the intestinal compartment through pattern recognition receptors such as TLRs. "
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    • "Intestinal microorganisms are crucially involved in the induction and modulation of mucosal tolerance (Noverr and Huffnagle, 2004; Sanz and De Palma, 2009; Peterson and Cardona, 2010; Tlaskalová-Hogenová et al., 2011; Huang et al., 2013; Ma et al., 2015). Alterations in mucosal tolerance induced by imbalanced gut microflora may lead to acute or chronic inflammation (Sanz and De Palma, 2009; Chow et al., 2010; Lee and Mazmanian, 2010; Jarchum and Pamer, 2011; Swiatczak and Rescigno, 2012; Magrone and Jirillo, 2013; Chistiakov et al., 2015). The effects of imbalanced microbiota are not restricted by gastrointestinal abnormalities but could have systemic impact on immunity (Noverr and Huffnagle, 2004; Huang et al., 2013; Ma et al., 2015). "
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