TB Diagnosis Based on Promiscuous PE-PGRS Epitopes

基于混杂 PE-PGRS 表位的结核病诊断

• 批准号: 7798073
• 负责人: Suman Laal
• 金额: $ 21.13万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-04-01 至 2011-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7798073
• 关键词: Acid Fast Bacillae Staining Method; Aerosols; Alanine; Amino Acids; Antibodies; Antigens; Bacillus (bacterium); Bedside Testings; Cell Wall; Cessation of life; Clinical; Code; Communities; Complex; Country; Development; Diagnosis; Diagnostic; Diagnostic tests; Environment; Epidemic; Epitope Mapping; Epitopes; Family; Generations; Genes; Genome; Glycine; Goals; Growth; HIV; HIV Antibodies; Immune response; Immunodominant Epitopes; Individual; Lead; Length; Link; Lung; Maps; Measures; Microscopic; Microscopy; Mycobacterium tuberculosis; Open Reading Frames; Opportunistic Infections; Oryctolagus cuniculus; Patients; Peptides; Protein Family; Proteins; Pulmonary Tuberculosis; Rage; Reporting; Resources; Reverse Transcriptase Polymerase Chain Reaction; Sensitivity and Specificity; Serum; Specificity; Specimen; Sputum; Staging; Subcellular Fractions; Testing; Time; Transcript; Tuberculosis; Western Blotting; Work; base; combat; immunogenic; improved; interest; latent infection; meetings; mycobacterial; pathogen; programs; public health relevance; vaccination against tuberculosis

DESCRIPTION (provided by applicant): A simple sensitive and specific point-of-care test that can diagnose TB in both HIV- and HIV+ subjects is urgently needed for combating the raging TB epidemic. A subfamily of genes, called PE-PGRS genes is present in M. tuberculosis (complex), but there are no PE-PGRS genes in several other common mycobacterial pathogens including M. avium (which afflicts 5-7% of the HIV+ subjects) and M. leprae. This makes the PE-PGRS proteins attractive targets for inclusion into diagnostic tests for TB. Our preliminary studies demonstrate that immunodominant epitopes that are shared by several PE-PGRS proteins (promiscuous epitopes) are highly immunogenic in TB patients. Based on these results we propose to identify the PE-PGRS genes that are highly expressed in the lungs of tuberculous rabbits infected with aerosols of clinical isolates of M. tuberculosis, and map their immunodominant promiscuous epitopes recognized specifically by antibodies from HIV-TB+ and HIV+TB+ patients. These epitopes can be the basis of a simple peptide-based diagnostic test for TB. Specifically, we propose to: a) Identify the subset of PE-PGRS genes that is highly expressed by M. tuberculosis during growth and replication in lungs, and characterize the proteins (Aim #1); b) Dissect the PEPGRS proteins selected in Aim # 1 to delineate the immunodominant epitopes that are recognized by serum antibodies from HIV-TB+ and HIV+TB+ patients but not by PPD-, PPD+ and/or BCG vaccinated healthy subjects or HIV+TB- controls (Aim #2) and c) Evaluate the reactivity of epitopes identified in Aim #2 with sera from individual patients at different stages of TB to identify the optimal set of peptides and evaluate the optimal peptide-subset for reactivity with sera from patients from different geographical settings (Aim # 3). PUBLIC HEALTH RELEVANCE: The work proposed could lead to development of a cheap, reliable and rapid diagnostic test for TB. No reliable rapid tests for TB exist so far and this would be a major advancement in the field.

描述（由申请人提供）：为了对抗肆虐的结核病流行，迫切需要一种简单、敏感、特异的即时检测，可以诊断 HIV 感染者和 HIV+ 受试者的结核病。结核分枝杆菌（复合型）中存在一个称为 PE-PGRS 基因的基因亚家族，但其他几种常见分枝杆菌病原体中没有 PE-PGRS 基因，包括鸟分枝杆菌（影响 5-7% 的 HIV+ 受试者）和麻风分枝杆菌。这使得 PE-PGRS 蛋白成为结核病诊断测试中有吸引力的靶标。我们的初步研究表明，几种 PE-PGRS 蛋白共享的免疫显性表位（混杂表位）在结核病患者中具有高度免疫原性。基于这些结果，我们建议鉴定在感染结核分枝杆菌临床分离株气溶胶的结核兔肺部中高表达的 PE-PGRS 基因，并绘制其免疫显性混杂表位图谱，这些表位可被 HIV-TB+ 和 HIV+TB+ 患者的抗体特异性识别。这些表位可以作为简单的基于肽的结核病诊断测试的基础。具体来说，我们建议： a) 鉴定结核分枝杆菌在肺部生长和复制过程中高度表达的 PE-PGRS 基因子集，并表征蛋白质（目标#1）； b) 剖析目标 #1 中选择的 PEPGRS 蛋白，以描绘被 HIV-TB+ 和 HIV+TB+ 患者的血清抗体识别的免疫显性表位，但不能被 PPD-、PPD+ 和/或 BCG 疫苗接种的健康受试者或 HIV+TB-对照者识别（目标 #2）；以及 c) 评估目标 #2 中鉴定的表位与血清的反应性 从结核病不同阶段的个体患者中提取数据，以确定最佳肽集，并评估最佳肽子集与来自不同地理环境的患者血清的反应性（目标＃3）。公共卫生相关性：拟议的工作可能会导致开发出一种廉价、可靠和快速的结核病诊断测试。迄今为止，还没有可靠的结核病快速检测方法，这将是该领域的重大进步。