Characterization of an M. tuberculosis vaccine

结核分枝杆菌疫苗的表征

• 批准号: 6835662
• 负责人: Chinnaswamy Jagannath
• 金额: $ 37.13万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-01-01 至 2006-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6835662
• 关键词: Mycobacterium tuberculosis; SCID mouse; antigen antibody reaction; antigen presentation; biotechnology; drug screening /evaluation; guinea pigs; laboratory mouse; molecular cloning; polymerase chain reaction; protein structure; tuberculosis vaccines; vaccine development

Tuberculosis is resurgent in most of the world fueled by drug resistance, AIDS, poverty and mobility. The goal of this project is to produce an improved vaccine. It is based on our observations that an antigen 85A deletion mutant of MTB strain H37Rv (Ag85A-) is markedly attenuated and has increased antigen presenting capability. Our rationale has three components: First, the most effective immunity known against tuberculosis is provided by prior infection with MTB itself. Consequently, we propose that an appropriately attenuated MTB will approach the natural limit of efficacy of vaccines for tuberculosis. Second, MTB inhibits phagosome-lysosome (P-L) fusion. Preliminary data demonstrates that deletion of the Ag85A gene of MTB restores P-L fusion, enhances antigen presentation and probably increases the immunogenicity of MTB. Third, since MTB is a clonal organism with no demonstrated ability for horizontal transfer of genes, the safety of attenuated MTB can be assured. The specific aims are: 1) Evaluate the efficacy and safety of the Ag85A-mutant as a vaccine against tuberculosis. The efficacy (ability to limit primary infection and dissemination) will be investigated by single or multiple immunizations of C57BL/6 mice, outbred mice and guinea pigs prior to aerosol challenge with virulent MTB. Safety will be evaluated by infection of a spectrum of animals including guinea pigs that are naturally more susceptible to disease, genetically heterogeneous outbred mice, immunocomormized SCID mice and steroid treated mice. Safety will be evaluated in terms the capacity of the vaccine organism to produce disease and its effect on persistence and pathogenicity of wild type MTB following challenge. 2) Introduce additional deletion mutations into the Ag85A- strain to improve safety while maintaining immunogenicity. We anticipate that any vaccine with prolonged survival in tissue may produce disease in immunosuppressed people. Consequently, attempts will be made to produce a double knockout mutant MTB that retains the immunogenicity of Ag85A- and is unable to survive in tissue. The 16 kDa alpha crystallin protein gene and nitrate reductase gene will be targeted. We anticipate that a safe live attenuated MTB vaccine with enhanced immunogenicity will prove valuable in combating adult pulmonary tuberculosis as well primary disease.

结核病在世界上大多数地区都以耐药性，艾滋病，贫困和流动性为动力而复兴。 该项目的目的是生产改进的疫苗。 这是基于我们的观察结果，即MTB菌株H37RV（AG85A-）的抗原85A缺失突变体被显着减弱，并增加了抗原表现能力。 我们的原理具有三个组成部分：首先，对结核病的最有效免疫是由MTB本身事先感染提供的。 因此，我们建议适当减弱的MTB接近疫苗对结核病的自然限制。 其次，MTB抑制吞噬体 - 溶酶体（P-L）融合。 初步数据表明，MTB的AG85A基因的缺失恢复了P-L融合，增强了抗原表现并可能增加MTB的免疫原性。 第三，由于MTB是一种克隆生物，没有表现出基因水平转移的能力，因此可以确保衰减的MTB的安全性。 具体目的是：1）评估AG85A突变剂作为针对结核病的疫苗的功效和安全性。 在与有毒MTB的气溶胶挑战之前，将研究疗效（限制原发性感染和传播的能力），通过C57BL/6小鼠的单个或多个免疫接种，近传小鼠和豚鼠。将通过感染一系列动物来评估安全性，包括豚鼠自然更容易受到疾病的影响，遗传异质性杂交小鼠，免疫成像SCID小鼠和类固醇治疗的小鼠。 在挑战之后，将以疫苗生物的产生疾病的能力及其对野生型MTB的持久性和致病性的影响进行评估。 2）将其他缺失突变引入AG85A-菌株中，以提高安全性，同时保持免疫原性。 我们预计，任何在组织中生存延长的疫苗都可能在免疫抑制人群中产生疾病。 因此，将尝试产生双基因敲除突变体MTB，该突变体MTB保留AG85A-的免疫原性，并且无法在组织中生存。 将靶向16 kDaα晶体蛋白蛋白基因和硝酸盐还原酶基因。 我们预计，具有增强免疫原性的安全活体衰减MTB疫苗将在对抗成人肺结核以及原发性疾病方面有价值。