Tuning of skin immunity by skin commensal bacteria.

Evaluation of: Naik S, Bouladoux N, Wilhelm C et al. Compartmentalized control of skin immunity by resident commensals. Science 337, 1115-1119 (2012). Most analyses of commensal microbiota have been directed toward the gut microbiota and its role in the development of the intestinal immune system, and in regulating the immune response at sites distant from the gut, including the joints or CNS. However, very little is known about how other niches of commensal microbiota affect local immunity and whether they are influenced by the gut microbiota. The current paper reveals that skin commensals are required for the development of protective immunity against a cutaneous pathogen. This immune response driven by skin commensals occurs independently of the gut microbiota and is mediated by MyD88 and IL-1 signaling that promotes protective effector T-cell responses.