Study of the immune response characteristics of Brucella Omp2b dominant T-B combined antigen epitope
LI Da-wei1, ZHU Yue-jie2, HUO Yi-shan3, LI Zhi-wei2, JIANG Xiao-ming1, SHA Tong4, CHEN Zhi-qiang4, ZHANG Feng-bo2, DING Jian-bing4
1. Department of Clinical Laboratory, The Fifth Affiliated Hospital of Xinjiang Medical University, Urumqi 830011, China; 2. Department of Clinical Laboratory, The First Affiliated Hospital of Xinjiang Medical University, Urumqi 830054, China; 3. Department of Clinical Laboratory, The Third Affiliated Hospital of Xinjiang Medical University, Urumqi 830001, China; 4. Department of Immunology, Basic Medical College, Xinjiang Medical University, Urumqi 830011, China
Abstract:The dominant B cell epitopes and T cell epitopes of Omp2b protein were predicted and analyzed through bioinformatics technology, and T-B combined antigen epitopes were screened to explore their immunogenicity and immune response characteristics, thus laying a foundation for the development of an effective Brucella vaccine. The bioinformatics software programs ProtParam, SOMPA, Swiss-model, Rasmol, DNAStar, SYFPEITHI and IEDB were used to analyze the structure of the Omp2b protein and predict the dominant epitopes of T cells and B cells, as well as the T-B combined epitopes. The number of IFN-γ positive cells was detected with the ELISPOT method. ELISA was used to detect the specific IgG antibody level of Omp2b T-B combined peptide in the serum of patients with brucella infection. In vitro culture of immune cells was performed, and perforin and granulase B were detected in the supernatant. Bioinformatics software was used to comprehensively analyze Omp2b protein, and a potential segment at positions 196-216 of the T-B cell combined antigen epitope was screened out. The number of IFN-γ cells (SFU) secreted in the patient group was significantly higher than that in the healthy control group (F=25.413,P<0.01). Serum levels of IgG antibodies, perforin and granulase B in patients with brucellosis were also significantly elevated (F=13.653,P<0.01). The T-B combined epitope of Omp2b protein produces a specific humoral immune response and cellular immune response, thus providing a reference for the selection and construction of a Brucella epitope vaccine.
[1] Byndloss MX, Tsolis RM.Brucella spp. virulence factors and immunity[J]. Annu Rev Anim Biosci, 2016, 4:111-127. DOI:10.1146/annurev-animal-021815-111326 [2] Zhang H, Dou X, Li Z, et al.Expression and regulaion of the eryoperon of Brucella melitensis in human trophoblast cells[J]. Exp Ther Med, 2016, 12(4):2723-2728. DOI:10.3892/etm.2016.3688 [3] Li T, Liu T, Jiang Z, et al.Diagnosing pyogenic, brucella and tuberculous spondylitis using histopathology and MRI:A retrospective study[J]. Exp Ther Med, 2016, 12(4):2069-2077. DOI:10.3892/etm.2016.3602 [4] 中华人民共和国国家卫生和计划生育委员会.中华人民共和国传染病防治法[EB/OL]. (2004-08-28)[2017-04-28].http://www.nhfpc.gov.cn/zwgkzt/pfl/200804/29124.shtml. [5] Golshani M, Rafati S, Nejati-Moheimani M, et al.Comparison of potential protection conferred by three immunization strategies (protein/protein, DNA/DNA, and DNA/protein) against Brucella infection using Omp2b in BALB/c Mice[J]. Veter Microbiol, 2016, 197:47-52. DOI:10.1016/j.vetmic.2016.10.027 [6] 李智伟,张峰波,卢佩佩,等.羊种布鲁氏菌OMP16蛋白结构的生物信息学分析[J].中国人兽共患病学报,2019,35(1):21-27,33. DOI:10.3969/j.issn.1002-2694.2018.00.214 [7] 陈志强,沙桐,李智伟,等.布鲁氏菌Omp25蛋白抗原表位的生物信息学分析[J].新疆医科大学学报,2020,43(4):414-418. DOI:10.3969/j.issn.1009-5551.2020.04.009 [8] Zhang F, Li ZW, Jia B, et al.The immunogenicity of OMP31 peptides and its protection against Brucella melitensis infection in mice[J]. Sci Rep, 2019,9(1):3512. DOI: 10.1038/s41598-019-40084-w [9] 李智伟,沙桐,蔺志强,等.IL-33和ST2在急慢性布鲁氏菌病中的变迁[J].新疆医科大学学报,2020,43(3):291-294. DOI:0.3969/j.issn.1009G5551.2020.03.014 [10] Crowcroft NS, Klein NP.A framework for research on vaccine effectiveness[J]. Vaccine, 2018, 36(48):7286-7293. DOI:10.1016/j.vaccine.2018.04.016 [11] Kim WK, Moon JY, Cho JS, et al.Protective efficacy by various doses of a new brucellosis vaccine candidate based on Salmonella strains expressing Brucella abortus BSCP31, Omp3b and superoxide dismutase against brucellosis in murine model[J]. Pathog Dis, 2017, 75(7). DOI:10.1093/femspd/ftx094 [12] 蔺志强,张蕊,秦莹,等.急慢性布鲁氏菌病患者Th1/Th2细胞及相关转录因子研究[J].新疆医科大学学报,2020,43(1):17-20. [13] 李智伟,丁剑冰.巨噬细胞极化特点及其在胞内菌感染中免疫调节功能的研究进展[J].中国免疫学杂志,2019,35(20):2554-2558. [14] Sanchez-Trincado JL, Marta GP, Reche PA.Fundamentals and methods for T- and B-Cell epitope prediction[J]. J Immunol Res, 2017, 2017:1-14. DOI:10.1155/2017/2680160 [15] Ahmed W, Zheng K, Liu ZF.Establishment of chronic infection: Brucella’s stealth strategy[J]. Front Cell Infect Microbiol, 2016, 6:30. DOI:10.3389/fcimb.2016.00030 [16] Vita R, Overton J A, Greenbaum J A, et al.The immune epitope database (IEDB) 3.0[J]. Nucleic Acids Research, 2015, 43(D1):D405-D412. DOI:10.1093/nar/gku938 [17] Di Carluccio AR, Triffon CF, Chen W.Perpetual complexity: predicting human CD8+ T cell responses to pathogenic peptides[J]. Immunol Cell Biol, 2018,96(4):358-369. DOI:10.1111/imcb.12019 [18] Shen C, Zhu B, Deng Y, et al.Allele polymorphism and haplotype diversity of HLA-A, -B and -DRB1 loci in sequence-based typing for chinese uyghur ethnic group[J]. PLoS One, 2010, 5(11):e13458. DOI:10.1371/journal.pone.0013458 [19] 沙桐,陈志强,李智伟,等.新疆儿童布鲁氏菌病的临床特征[J].新疆医科大学学报,2020,43(2):193-195,200. [20] Lenka P, Mangesh B, Borszekova PL.An introduction to B-cell epitope mapping and in silico epitope prediction[J]. J Immunol Res, 2016, 2016:1-11. DOI:10.1155/2016/6760830 [21] Wang HW, Pai TW.Machine learning-based methods for prediction of linear B-cell epitopes[J]. Meth Mole Biol, 2014, 1184:217-236. DOI:10.1007/978-1-4939-1115-8_12