无乳链球菌甘油醛-3-磷酸脱氢酶C的B细胞抗原表位预测与鉴定  

Prediction and Identification of B Cell Epitopes ofGapC Protein of Streptococcus agalactiae

作　　者：李胜男 王汉青 吕芬芬 赵海利 苏艳[1] LI Sheng-nan;WANG Han-qing;LV Fen-fen;ZHAO Hai-li;SU Yan(College of Veterinary Medicine,Xinjiang Agricultural University,Urumqi 830052,China;Agricultural and Rural Beurau of Zhaosu County,Xinjiang,Zhaosu 835500,China)

机构地区：[1]新疆农业大学动物医学学院,乌鲁木齐830052 [2]新疆昭苏县农业农村局,昭苏835500

出　　处：《新疆农业大学学报》2023年第4期277-284,共8页Journal of Xinjiang Agricultural University

基　　金：新疆维吾尔自治区高校科研计划重点项目(XJEDU2018I1009)。

摘　　要：旨在表达牛源无乳链球菌(Streptococcus agalactiae)甘油醛-3-磷酸脱氢酶C (GapC)蛋白并对其免疫效果进行评估,预测并鉴定其优势B细胞抗原表位。本研究对无乳链球菌X16087株的GapC基因扩增,构建重组质粒pET-28a-WR-X16087,经诱导表达后纯化GapC蛋白,免疫小鼠并分析免疫效果。对GapC蛋白进行生物信息学分析,预测并鉴定其B细胞表位。结果表明,重组质粒经诱导表达纯化后,获得大小为44 kDa的目的蛋白,免疫小鼠后抗体效价可达1∶218 700,抗体亚型以IgG1和IgG2b为主;小鼠免疫后保护率可达100%;GapC免疫后可显著减少攻击后小鼠肝、脾、肺、肾中的菌体载量;GapC蛋白可减少细菌入侵对小鼠造成病理损伤。预测并筛选了GapC的B细胞表位,确定了3个具有良好抗原性的B细胞线性表位,分别为:~(46)KYDTTQGRFDGTVEVKDG~(63)、~(121)TAPGGNDV~(128)、~(186)MVLDGPHRGGDLRRAR~(201)。鉴定表明,3个B细胞表位有成为牛源无乳链球菌预防性表位疫苗的潜力。To express the Glyceraldehyde-3-Phosphate Dehydrogenase(GapC)protein of Streptococcus agalactiae from bovine and evaluate its immune effect,predict and identify its dominant B cell epitope.In this study,the GapC gene of Streptococcus agalactiae X16087 strain was amplified and the recombinant plasmid pET-28a-WR-X16087 was constructed.After induction and expression,purified GapC protein was used to immunize mice and the immune effect was analyzed.Then bioinformatics analysis was performed to predict and identify the B cell epitopes of GapC protein.The results showed that after induction and purification,the target protein with a size of 44 kDa was obtained.After immunizing,the mice antibody titer reached 1∶218700,and the antibody subtypes mainly were IgG1 and IgG2b;mice protection could reach 100%.GapC immunization could significantly reduce the bacterial load in liver,spleen,lung and kidney of mice.GapC protein could reduce the pathological damage caused by bacterial invasion in mice.The B cell epitopes of GapC were predicted and screened.Based on the specific antibodies,three linear B cell epitopes of GapC were identified:46 KYDTTQGRFDGTVEVKDG 63,121 TAPGGNDV 128,186 MVLDGPHR-GGDLRRAR 201.The finding showed that the three B cell epitopes had the potential to be used in prophylactic epitope vaccines against bovine mastitis of Streptococcus agalactiae.

关 键 词：无乳链球菌 GapC蛋白 免疫效果 B细胞表位 筛选与鉴定 

分 类 号：S852.4[农业科学—基础兽医学]