Autore: Akira Nakajima, Alexis Vogelzang, Mikako Maruya, Michio Miyajima, Megumi Murata, Aoi Son, Tomomi Kuwahara, Tatsuaki Tsuruyama, Satoshi Yamada, Minoru Matsuura, Hiroshi Nakase, Daniel A. Peterson, Sidonia Fagarasan, and Keiichiro Suzuki
Rivista: Journal of Experimental Medicine
Immunoglobulin A (IgA) promotes health by regulating the composition and function of gut microbiota, but the molecular requirements for such homeostatic IgA function remain unknown. We found that a heavily glycosylated monoclonal IgA recognizing ovalbumin coats Bacteroides thetaiotaomicron (B. theta), a prominent gut symbiont of the phylum Bacteroidetes. In vivo, IgA alters the expression of polysaccharide utilization loci (PUL), including a functionally uncharacterized molecular family provisionally named Mucus-Associated Functional Factor (MAFF). In both mice and humans, MAFF is detected predominantly in mucus-resident bacteria, and its expression requires the presence of complex microbiota. Expression of the MAFF system facilitates symbiosis with other members of the phylum Firmicutes and promotes protection from a chemically induced model of colitis. Our data reveal a novel mechanism by which IgA promotes symbiosis and colonic homeostasis.
IgA regulates the composition and metabolic function of gut microbiota by promoting symbiosis between bacteria