幽门螺杆菌尿素酶B亚单位优势Th表位的系统筛选与鉴定  

Systemic identification of immunodominant Th epitopes from urease B subunit of Helicobacter pylori

作　　者：李滨[1] 陈立[1] 杨武晨[2] 李海波[1] 胡健[2] 何亚非[2] 章金勇[1] 赵卓[1] 吴超[1] 

机构地区：[1]第三军医大学医学检验系临床微生物学及免疫学教研室国家免疫生物制品工程技术研究中心,重庆400038 [2]第三军医大学新桥医院消化内科,重庆400037

出　　处：《第三军医大学学报》2013年第3期212-215,共4页Journal of Third Military Medical University

基　　金：国家自然科学基金(81072493);重庆市自然科学基金(CSTC2011BB5043)~~

摘　　要：目的筛选幽门螺杆菌(Helicobacter pylori,Hp)尿素酶B亚单位(UreB)中CD4+细胞优势应答表位,并确定其MHC限制性。方法以重组UreB蛋白(rUreB)与弗氏佐剂联合皮下多点注射免疫BALB/c小鼠,从小鼠脾脏中体外扩增UreB特异性T淋巴细胞,采用步移重叠合成肽法筛选CD4+T细胞优势应答表位,分析其MHC分子限制性。结果 18mer短肽筛选发现UreB403-420和UreB409-426可显著刺激UreB特异性CD4+T细胞产生IFN-γ。13mer短肽鉴定实验结果显示,UreB409-421可刺激产生与18mer短肽UreB403-420和UreB409-426等同的应答强度。同时抗体阻断实验表明,抗H-2d(I-A)单克隆抗体能有效阻断该表位的应答。结论 UreB403-420和UreB409-426为UreB抗原中的优势Th表位,其刺激免疫反应的核心位置为UreB409-421,且存在H-2d(I-A)限制性。Objective To identify systematically MHC-restricted immunodominant T helper lympho- cyte （Th） epitopes from urease subunit B of Helicobacterpylori （11. pylori） and to confirm the MHC-restricting profile. Methods BALB/e mice were immunized with recombinant UreB protein （rUreB） and Freund＇ s adjuvant by subcutaneous injection. Antigen-specific CD4 ＋ T cells were amplified in vitro from spleens of immunized mice. The MHC-restricted immunodominant Th epitopes were identified by synthesizing overlapping peptides and antibody-blocking assay. Results UreBa03-42oand UreB4og-426 induced the strongest secretion of IFN-r in all the 93 18mer peptides, while 13mer peptide UreB403_426 within UreB4o3-42o and UreB4o9-426 induced equivalent responses compared with the 18mer peptides. The results of antibody-blocking assay showed that the H-2d（I-A） monoclonal antibody efficiently blocked the T cell activation induced by peptide UreB403-426. Conclusion UreB403-420 and UreB4og_426 are immunodominant Th epitopes of urease subunit B antigen. The core reactive sequence is UreB409-421, and its restriction molecule is H-2a（I-A）.

关 键 词：幽门螺杆菌 尿素酶B亚单位 TH表位 

分 类 号：R377[医药卫生—病原生物学] R392.33[医药卫生—基础医学]