title: Fostering of advanced mutualism with gut microbiota by Immunoglobulin A.
abstract: Immunoglobulin A (IgA), the most abundantly secreted antibody isotype in mammals, not only provides direct immune protection to neonates via maternal milk but also helps program the infant immune system by regulating the microbiota. IgA continues to maintain dynamic interactions with the gut microbiota throughout life and this influences immune system homeostasis as well as other physiological processes. The secretory IgA produced independently of T-cell selection are commonly referred to as natural or innate antibodies. Our studies have shown that innate-IgA, while effective at excluding microorganisms from the gut, does not promote mutualism with the microbiota in the same way as adaptive-IgA that is selected in T cell-dependent germinal center reactions. Adaptive-IgA fosters more advanced mutualism with the microbiota than innate-IgA by selecting and diversifying beneficial microbial communities. In this review, we suggest that the diversified microbiota resulting from adaptive-IgA pressure was pivotal in promoting ecological adaptability and speciation potential of mammals.
authors: Laboratory of Intestinal Immunology, Global Health Institute, School of Life Sciences, Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland.
authors: Duncan B
authors: DB
authors: Sutherland
authors: Center for Innovation in Immunoregulative Technology and Therapeutics, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors: Keiichiro
authors: K
authors: Suzuki
authors: Laboratory for Mucosal Immunity, Center for Integrative Medical Sciences (IMS), RIKEN Yokohama Institute, Yokohama, Japan.
authors: Sidonia
authors: S
authors: Fagarasan
mesh_terms: D000220:Adaptation, Biological / Q000276:immunology; D000818:Animals; D003564:Cytidine Deaminase / Q000378:metabolism; D000069196:Gastrointestinal Microbiome / Q000276:immunology*; D006706:Homeostasis; D006801:Humans; D007112:Immunity, Maternally-Acquired; D007070:Immunoglobulin A / Q000276:immunology* / Q000378:metabolism; D007071:Immunoglobulin A, Secretory / Q000276:immunology; D056747:Immunomodulation; D013559:Symbiosis; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D000098830:AICDA (Activation-Induced Cytidine Deaminase)
chemical_list: D007070:Immunoglobulin A; D007071:Immunoglobulin A, Secretory; D000098830:AICDA (Activation-Induced Cytidine Deaminase); D003564:Cytidine Deaminase
keywords: IgA; evolution; homeostasis; immune regulation; microbiota