Singh Krishna K, Sharma Naresh, Vargas Diana, Liu Zhentong, Belisle John T, Potharaju Visalakshi, Wanchu Ajay, Behera Digambar, Laal Suman
Department of Pathology, New York University School of Medicine, New York, NY 10010, USA.
J Infect Dis. 2009 Aug 15;200(4):571-81. doi: 10.1086/603539.
The sequencing of the Mycobacterium tuberculosis genome revealed the existence of several genes encoding novel proteins with unknown functions, one of which is the proline-threonine repetitive protein (PTRP; Rv0538). Genomic studies of various mycobacterial species and M. tuberculosis clinical isolates demonstrate that ptrp is specific to the M. tuberculosis complex and ubiquitous in clinical isolates. Enzyme-linked immunosorbent assay, Western blot analysis, and electron microscopic evaluation of M. tuberculosis subcellular fractions and intact bacteria confirm that PTRP is a cell wall protein. Antibodies to PTRP are present in serum specimens from human immunodeficiency virus (HIV)-negative, tuberculosis (TB)-positive and HIV-positive, TB-positive patients but not purified protein derivative (PPD)-negative or PPD-positive healthy control subjects, demonstrating its diagnostic potential. Epitope mapping of PTRP delineated 4 peptides that can identify >80% of sputum smear-positive and >50% of smear-negative, HIV-negative, TB-positive patients and >80% of HIV-positive, TB-positive patients. These results demonstrate that immunodominant epitopes of carefully selected M. tuberculosis-specific proteins can be used to devise a simple peptide-based serodiagnostic test for TB.
结核分枝杆菌基因组测序揭示了几个编码功能未知的新蛋白的基因的存在，其中之一是脯氨酸 - 苏氨酸重复蛋白（PTRP；Rv0538）。对各种分枝杆菌物种和结核分枝杆菌临床分离株的基因组研究表明，ptrp对结核分枝杆菌复合群具有特异性，并且在临床分离株中普遍存在。对结核分枝杆菌亚细胞组分和完整细菌进行的酶联免疫吸附测定、蛋白质印迹分析和电子显微镜评估证实，PTRP是一种细胞壁蛋白。来自人类免疫缺陷病毒（HIV）阴性、结核病（TB）阳性以及HIV阳性、TB阳性患者的血清标本中存在针对PTRP的抗体，但纯化蛋白衍生物（PPD）阴性或PPD阳性的健康对照受试者血清中不存在，这表明了其诊断潜力。PTRP的表位作图确定了4种肽，这些肽可识别>80%的痰涂片阳性以及>50%的涂片阴性、HIV阴性、TB阳性患者和>80%的HIV阳性、TB阳性患者。这些结果表明，精心选择的结核分枝杆菌特异性蛋白的免疫显性表位可用于设计一种简单的基于肽的结核病血清诊断试验。
