鸡恒定链功能片段跨物种增强小鼠对新城疫F2抗原免疫作用的研究  

Cross species enhancement of mice antigen immune function against NDV-F2 by invariant chain functional fragments of chicken

作　　者：王琛[1] 刘雪兰[1] 陈芳芳[1] 余为一[1] 

机构地区：[1]安徽农业大学安徽省人兽共患病重点实验室,安徽合肥230036

出　　处：《西北农林科技大学学报（自然科学版）》2014年第5期33-38,共6页Journal of Northwest A&F University(Natural Science Edition)

基　　金：国家自然科学基金项目(31172306);安徽省自然科学基金项目(11040606M90)

摘　　要：【目的】研究恒定链（Invariant chain,Ii）功能片段作为载体的跨物种免疫增强作用及其潜在机制。【方法】构建基于鸡Ii功能片段与新城疫病毒抗原表位F2的嵌合体（Ii-F2、Cyt/Tm/Ii-key/F2/AP、Tm/Ii-key/F2/AP、Ii-key/F2/AP、Ii-key/F2）,将其定向克隆至原核表达载体pET-32a中,转化大肠杆菌Rosetta（DE3）并用IPTG诱导表达,嵌合体融合蛋白纯化后免疫小鼠,用ELISA法测定血清抗体效价。同时,分别构建含鸡Ii和小鼠MHCⅡ类分子基因的真核表达载体,并将其共转染COS7细胞,通过激光共聚焦显微镜观察其在细胞内的共定位。【结果】用F2与Ii-key等Ii功能片段连接的融合蛋白免疫的试验组小鼠的抗体效价,较单独用F2抗原肽免疫的对照组小鼠产生的抗体效价提高了1.5~3倍。显微观察发现,鸡Ii和小鼠MHCⅡ分子在细胞内可以共定位。【结论】Ii具有跨越物种限制增强免疫的作用。[Objective] This study aimed to research the cross species enhancement of mice antigen im- mune function against NDV-F2 with the invariant chain functional segments of chicken as immune carrier. [ Method] Chimeras （Ii-F2, Cyt/Tm/Ii-key/F2/AP, Tm/Ii-key/F2/AP, Ii-key/F2/AP, Ii-key/F2） based on Ii and NDV epitope F2 were reconstructed before being inserted into the prokaryotic expression vector pET-32a and transformed into E. coli Rosetta （DE3）. The recombinant bacteria were induced to express the chimeric proteins by IPTG. Mice were immunized with the purified proteins and the antibody titers were measured by ELISA. Meanwhile,chicken Ii and mouse MHC class Ⅱα or β chain genes were cloned into the eukaryotic expression vector and co-transfected in COS？ cells before the intracellular association was determined by confocal laser scanning microscope （CLSM）. [Result] The mice immunized with these chimeric proteins increased antibody titers by 1. 5-3 times compared with those immunized with F2 alone. Chicken Ii could co-locate and bind with mouse MHC class Ⅱ molecule in the COS7 cells. [Conclusion] The Ii functional segments could be used as immune carrier to enhance the immune response.

关 键 词：恒定链 肽载体 嵌合体 异种免疫 

分 类 号：S858.315.3[农业科学—临床兽医学] S852.43[农业科学—兽医学]