Kaetzel Charlotte S
Department of Microbiology, Immunology and Molecular Genetics, 203 Combs Cancer Research Building, University of Kentucky College of Medicine, 800 Rose Street, Lexington, KY 40536, United States.
Immunol Lett. 2014 Dec;162(2 Pt A):10-21. doi: 10.1016/j.imlet.2014.05.008. Epub 2014 May 27.
Secretory IgA (SIgA) antibodies in the intestinal tract form the first line of antigen-specific immune defense, preventing access of pathogens as well as commensal microbes to the body proper. SIgA is transported into external secretions by the polymeric immunoglobulin receptor (pIgR). Evidence is reported here that the gut microbiota regulates production of SIgA and pIgR, which act together to regulate the composition and activity of the microbiota. SIgA in the intestinal mucus layer helps to maintain spatial segregation between the microbiota and the epithelial surface without compromising the metabolic activity of the microbes. Products shed by members of the microbial community promote production of SIgA and pIgR by activating pattern recognition receptors on host epithelial and immune cells. Maternal SIgA in breast milk provides protection to newborn mammals until the developing intestinal immune system begins to produce its own SIgA. Disruption of the SIgA-pIgR-microbial triad can increase the risk of infectious, allergic and inflammatory diseases of the intestine.
肠道中的分泌型免疫球蛋白A（SIgA）抗体构成了抗原特异性免疫防御的第一道防线，可防止病原体以及共生微生物进入人体内部。SIgA通过聚合免疫球蛋白受体（pIgR）转运至外分泌液中。本文报道了肠道微生物群调节SIgA和pIgR产生的证据，它们共同作用以调节微生物群的组成和活性。肠道黏液层中的SIgA有助于维持微生物群与上皮表面之间的空间隔离，同时又不损害微生物的代谢活性。微生物群落成员释放的产物通过激活宿主上皮细胞和免疫细胞上的模式识别受体来促进SIgA和pIgR的产生。母乳中的母体SIgA可为新生哺乳动物提供保护，直至发育中的肠道免疫系统开始产生自身的SIgA。SIgA-pIgR-微生物三联体的破坏会增加肠道感染性、过敏性和炎症性疾病的风险。
