金黄色葡萄球菌FnbpA的CD4^+ T细胞表位鉴定  

Identification of CD4^+ T-cell epitopes on FnbpA of Staphylococcus aureus in C57BL/6 mice

作　　者：王歆桐 近皖豫 李晓婷[2] 余崴 王梦瑶[1] 于思淼 姚笛[2] 孙虎男[1] 马金柱[1] 于立权[1] 张华[1] 崔玉东[1,2] 

机构地区：[1]黑龙江八一农垦大学生命科学技术学院,黑龙江大庆163319 [2]黑龙江八一农垦大学动物科技学院,黑龙江大庆163319

出　　处：《中国预防兽医学报》2017年第5期337-341,共5页Chinese Journal of Preventive Veterinary Medicine

基　　金：黑龙江省科学基金重点项目(ZD2016004)

摘　　要：金黄色葡萄球菌(S.aureus)表达的菌体表面纤连蛋白结合蛋白A(FnbpA)在感染早期与宿主细胞粘附过程中起关键作用,将其免疫小鼠后能够诱导机体产生强烈的Th1和Th17反应。但FnbpA诱导Th1和Th17反应的CD4^+ T细胞表位尚不清楚。本研究根据FnbpA二级结构及其与MHCⅡ分子的结合能力对CD4^+ T细胞表位进行预测与分析,选择并合成7个候选CD4^+ T细胞表位肽。将每个表位肽分别对FnbpA免疫的C57BL/6小鼠CD4^+ T细胞进行体外刺激,通过检测CD4^+ T细胞增殖及其分泌的细胞因子水平对免疫优势表位进行初步鉴定。再以初步鉴定的优势表位肽段免疫小鼠,并检测其诱导的特异性细胞免疫应答水平。结果表明,表位肽F5(FnbpA488-505)能够显著诱导CD4^+ T细胞增殖并分泌高水平IFN-γ和IL-17A,而且F5在不同S.aureus菌株中高度保守。表明FnbpA_(488-505)是诱导CD4^+ T细胞分化为Th1/Th17的T细胞表位。本研究为S.aureus的FnbpA表位肽疫苗的进一步设计提供了实验依据。Fibronectin-binding protein A （FnbpA） is a crucial surface protein of Staphylococcus aureus, which is able to adhere on host cells to induce a strong Th1 and Th17 responses in early stage of S.aureus infection. To identify the CD4^＋ T cell epitopesin S.aureus FnbpA, the seven predicted peptides in FnbpA were synthesized according to analysis of the binding affinity between MHC class II molecules and the CD4^＋ T-cell epitopes in S.aureus FnbpA by related bioinformatics softwares. Then, the lymphocyte collected from spleen of FnbpA immunized C57BL/6 （H-2b） mice were stimulated with the 7 synthesized peptides, respectively, and the ability to induce T-cell proliferation and cytokines response were detected to validate the activity of the peptides. The results showed that the peptides of F5 （FnbpA488-505） induced significantly higher cell proliferation and higher levels of IFN-γ and IL-17A responses than that of other peptides. These data demonstrate the peptide F5 of FnbpA488-505 is one of the T-cell epitopes in FnbpA of S.aureus to elicit immune responses in C57BL/6 mice. Inconclusion, our study provides important data for the further design of the FnBPA epitope peptide-based S.aureus vaccines.

关 键 词：金黄色葡萄球菌 纤连蛋白结合蛋白A CD4^+T细胞表位 辅助性T细胞1 辅助性T细胞177 

分 类 号：S852.61[农业科学—基础兽医学]