Duan Zhi-Liang, Li Qiang, Wang Sina, Chen Xin-Yu, Liu Hui-Fang, Chen Bo-Kun, Li De-Zhou, Huang Xi, Wen Jin-Sheng
Institute of Arboviruses, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, China.
Curr Microbiol. 2015 Jun;70(6):769-78. doi: 10.1007/s00284-015-0786-x. Epub 2015 Feb 15.
PPE68 is a Mycobacterium tuberculosis-specific protein which is absent from the vaccine strains of BCG. A panel of 14 PPE68-derived peptides predicted to bind to HLA-A0201 was synthesized. The HLA-A0201 restriction of these peptides was determined in T2 cell line and HLA-A0201 transgenic mice. The specificity of peptides was assessed in pulmonary tuberculosis (TB) patients using IFN-γ enzyme-linked immunospot (ELISPOT) assay, and immunodominant peptides were further used to evaluate their diagnostic potential in HLA-A0201-positive pulmonary TB patients. 13 out of 14 peptides were identified as high-affinity binders. Of these peptides, 12 peptides induced significant IFN-γ-secreting T cell response in transgenic mice and 9 peptides were efficiently recognized by peripheral blood mononuclear cells of 10 HLA-A0201-positive TB patients. Four immunodominant HLA-A0201-restricted epitopes (PPE68126-134, PPE68133-141, PPE68140-148, and PPE68148-156) were recognized by the most of 80 HLA-A*0201-positive TB patients (81, 86, 74, and 84 %, respectively). These epitopes may be used for a potential diagnosis of M. tuberculosis infection.
PPE68是一种结核分枝杆菌特异性蛋白,卡介苗疫苗株中不存在该蛋白。合成了一组预测可与HLA-A0201结合的14种源自PPE68的肽段。在T2细胞系和HLA-A0201转基因小鼠中确定了这些肽段的HLA-A0201限制性。使用干扰素-γ酶联免疫斑点(ELISPOT)试验在肺结核患者中评估了肽段的特异性,并进一步使用免疫显性肽段评估其在HLA-A0201阳性肺结核患者中的诊断潜力。14种肽段中有13种被鉴定为高亲和力结合剂。在这些肽段中,12种肽段在转基因小鼠中诱导了显著的分泌干扰素-γ的T细胞反应,9种肽段被10名HLA-A0201阳性肺结核患者的外周血单个核细胞有效识别。80名HLA-A0201阳性肺结核患者中的大多数(分别为81%、86%、74%和84%)识别出四种免疫显性的HLA-A*0201限制性表位(PPE68126-134、PPE68133-141、PPE68140-148和PPE68148-156)。这些表位可用于潜在的结核分枝杆菌感染诊断。