谷氨酰胺对细菌感染过程中虹鳟肠黏膜免疫球蛋白IgT的调控作用研究

鱼类细菌性肠炎多发给水产养殖业造成巨大损失，通过营养调控手段增强鱼体对病原抵抗力具有巨大优势；已有研究表明作为肠道主要能源物质之一的谷氨酰胺可以改善鱼体肠道健康、提高系统性免疫功能，但对鱼类肠黏膜特异性免疫调控机制研究还非常有限。因此本项目拟采用摄食生长法结合细菌感染试验，通过Western Blot、流式细胞术、Edu注射法、免疫荧光等技术，系统研究在鳗弧菌感染虹鳟过程中谷氨酰胺如何激活肠道细胞内相关信号通路来调控肠道IgT+和IgM+ B淋巴细胞的增殖和分化，进而促进免疫球蛋白IgT的分泌和效价以执行对入侵病原的免疫清除作用。这将有助于在一定程度上揭示鱼类营养代谢与肠黏膜特异性免疫应答之间相互关系，推动水产养殖业的健康可持续发展。

Intestinal inflammation induced by bacterial infection causes enormous losses to aquaculture industry, while enhancing the disease-resistance ability via nutritional modulation owns various advantages. Earlier studies have shown that glutamine, which serves as the main fuel source for intestine, can improve fish intestinal health and enhance systematic immunity; however, less is known about its role on the local immunity of fish intestine, especially its mucosal specific immunity. Thus our present program tries to evaluate the influence of dietary glutamine on cell signaling pathways of rainbow trout during bacterial infection with Vibrio anguillarum, and how these signaling pathways modulate the proliferation and differentiation of intestinal IgM+ B lymphocytes and IgT+ B lymphocytes, which finally results in increased secretion and titer of IgT within intestinal mucous to defend against the invasion of bacteria. Methods including western blot, flow cytometry, Edu injection and immunofluorescence would be adopted, with the combination of both nutritional study and bacterial infection study. With above research, our results would reveal the interaction between nutritional metabolism and intestinal mucosal specific immunity, and finally benefit the sustainable development of aquaculture.