Dishaw Larry J, Leigh Brittany, Cannon John P, Liberti Assunta, Mueller M Gail, Skapura Diana P, Karrer Charlotte R, Pinto Maria R, De Santis Rosaria, Litman Gary W
Department of Pediatrics, University of South Florida Morsani College of Medicine, Children's Research Institute, 140 7th Avenue South, St Petersburg, Florida 33701, USA.
College of Marine Sciences, University of South Florida St Petersburg, 140 7th Avenue South, St Petersburg, Florida 33701, USA.
Nat Commun. 2016 Feb 15;7:10617. doi: 10.1038/ncomms10617.
Protochordate variable region-containing chitin-binding proteins (VCBPs) consist of immunoglobulin-type V domains and a chitin-binding domain (CBD). VCBP V domains facilitate phagocytosis of bacteria by granulocytic amoebocytes; the function of the CBD is not understood. Here we show that the gut mucosa of Ciona intestinalis contains an extensive matrix of chitin fibrils to which VCBPs bind early in gut development, before feeding. Later in development, VCBPs and bacteria colocalize to chitin-rich mucus along the intestinal wall. VCBP-C influences biofilm formation in vitro and, collectively, the findings of this study suggest that VCBP-C may influence the overall settlement and colonization of bacteria in the Ciona gut. Basic relationships between soluble immunoglobulin-type molecules, endogenous chitin and bacteria arose early in chordate evolution and are integral to the overall function of the gut barrier.
原索动物含可变区的几丁质结合蛋白（VCBPs）由免疫球蛋白型V结构域和一个几丁质结合结构域（CBD）组成。VCBP的V结构域促进粒细胞性变形细胞对细菌的吞噬作用；CBD的功能尚不清楚。在这里，我们表明，玻璃海鞘的肠道黏膜含有大量几丁质原纤维基质，在肠道发育早期、进食之前，VCBPs就会与之结合。在发育后期，VCBPs和细菌共定位于沿肠壁富含几丁质的黏液中。VCBP-C在体外影响生物膜形成，总体而言，本研究结果表明，VCBP-C可能影响玻璃海鞘肠道中细菌的整体定植和定殖。可溶性免疫球蛋白型分子、内源性几丁质和细菌之间的基本关系在脊索动物进化早期就已出现，并且是肠道屏障整体功能不可或缺的一部分。
