Department of Zoology, Hansraj College, University of Delhi, India.
Microb Pathog. 2021 Aug;157:104996. doi: 10.1016/j.micpath.2021.104996. Epub 2021 May 24.
Identification of protective antigens for designing a high-efficacy tuberculosis vaccine is the need of the hour. Till date only 7% of the Mycobacterium tuberculosis proteome has been explored for discovering antigens capable of activating T-cell responses. Therefore, it becomes crucial to screen the remaining Mycobacterium tuberculosis proteome for more immunodominant T-cell epitopes. An extensive knowledge of the epitopes recognized by our immune system can aid this process of finding potential T cell antigens for development of a better TB vaccine. In the present in-silico study, 237 proteins belonging to the 'virulence, detoxification, and adaptation' category of Mycobacterium tuberculosis proteome were targeted for T-cell epitope screening. 50825 MHC Class I and 49357 MHC Class II epitopes were generated using NetMHC3.4 and IEDB servers respectively and tested for their antigenicity and cytokine stimulation. The highest antigenic epitopes were analyzed for their world population coverage and epitope conservancy. Molecular docking and molecular dynamics simulation studies were performed to corroborate the binding affinities and structural stability of the peptide-MHC complexes. We predicted a total of 3 MHC Class I (ILLKMCWPA, FAVGMNVYV, and SLAGNSAKV) and 7 MHC Class II (DLTIGFFLHIPFPPV, RPDLTIGFFLHIPFP, LTIGFFLHIPFPPVE, VLVFALVVALVYLQF, LVFALVVALVYLQFR, PNLVAARFIQLTPVY, and LVLVFALVVALVYLQ) epitopes that can be promising vaccine candidates. These predicted epitopes belong to 6 distinct proteins: Rv0169 (mce1a), Rv3490 (ostA), Rv3496 (mce4D), Rv1085c, Rv0563 (HtpX), Rv3497c (mce4C). All these proteins are expressed at different stages in the life cycle of Mycobacterium tuberculosis and thus, the predicted epitopes could be employed as candidates for designing a multistage-multiepitopic vaccine.
鉴定保护性抗原以设计高效的结核病疫苗是当前的需求。迄今为止,仅探索了结核分枝杆菌蛋白质组的 7%,以发现能够激活 T 细胞反应的抗原。因此,筛选剩余的结核分枝杆菌蛋白质组以寻找更多免疫优势 T 细胞表位变得至关重要。对我们免疫系统识别的表位有广泛的了解可以辅助这一过程,从而为开发更好的结核病疫苗寻找潜在的 T 细胞抗原。在本计算机研究中,针对结核分枝杆菌蛋白质组的“毒力、解毒和适应”类别中的 237 种蛋白质进行了 T 细胞表位筛选。使用 NetMHC3.4 和 IEDB 服务器分别生成了 50825 个 MHC 类 I 和 49357 个 MHC 类 II 表位,并对其抗原性和细胞因子刺激进行了测试。对最高抗原性的表位进行了世界人群覆盖率和表位保守性分析。进行了分子对接和分子动力学模拟研究,以证实肽-MHC 复合物的结合亲和力和结构稳定性。我们总共预测了 3 个 MHC 类 I(ILLKMCWPA、FAVGMNVYV 和 SLAGNSAKV)和 7 个 MHC 类 II(DLTIGFFLHIPFPPV、RPDLTIGFFLHIPFP、LTIGFFLHIPFPPVE、VLVFALVVALVYLQF、LVFALVVALVYLQFR、PNLVAARFIQLTPVY 和 LLVLFALVVALVYLQ)表位,它们可能是有前途的疫苗候选物。这些预测的表位属于 6 种不同的蛋白质:Rv0169(mce1a)、Rv3490(ostA)、Rv3496(mce4D)、Rv1085c、Rv0563(HtpX)和 Rv3497c(mce4C)。所有这些蛋白质都在结核分枝杆菌生命周期的不同阶段表达,因此,预测的表位可以作为设计多阶段多表位疫苗的候选物。