Characterization of an M. tuberculosis vaccine

结核分枝杆菌疫苗的表征

基本信息

批准号：
6438079
负责人：
Chinnaswamy Jagannath
金额：
$ 36.84万
依托单位：
UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
依托单位国家：
美国
项目类别：
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/6438079
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

项目摘要

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.

在耐药性、艾滋病、贫困和流动性的推动下，结核病在世界大部分地区死灰复燃。该项目的目标是生产改进的疫苗。根据我们的观察，MTB菌株H37Rv（Ag85A-）的抗原85A缺失突变体显着减毒并且具有增强的抗原呈递能力。我们的基本原理由三个部分组成：首先，已知的最有效的抗结核免疫力是由先前感染 MTB 本身提供的。因此，我们建议适当减毒的 MTB 将接近结核病疫苗功效的自然极限。其次，MTB 抑制吞噬体-溶酶体 (P-L) 融合。初步数据表明，MTB Ag85A 基因的缺失可恢复 P-L 融合，增强抗原呈递，并可能增加 MTB 的免疫原性。第三，由于MTB是一种克隆生物，尚未证实具有基因水平转移能力，因此减毒MTB的安全性可以得到保证。具体目标是： 1) 评估 Ag85A 突变体作为结核病疫苗的有效性和安全性。在用强毒MTB进行气溶胶攻击之前，将通过对C57BL/6小鼠、远交小鼠和豚鼠进行单次或多次免疫来研究功效（限制原发感染和传播的能力）。安全性将通过一系列动物的感染进行评估，包括天然更容易感染疾病的豚鼠、遗传异质的远交小鼠、免疫复合性 SCID 小鼠和类固醇治疗的小鼠。安全性将根据疫苗生物体产生疾病的能力及其对攻击后野生型 MTB 的持久性和致病性的影响进行评估。 2) 在Ag85A-菌株中引入额外的缺失突变，以提高安全性，同时保持免疫原性。我们预计任何在组织中存活时间较长的疫苗都可能在免疫抑制的人群中产生疾病。因此，将尝试产生双敲除突变体MTB，其保留Ag85A-的免疫原性并且无法在组织中存活。 16 kDa α 晶状体蛋白基因和硝酸还原酶基因将成为目标。我们预计，具有增强免疫原性的安全 MTB 减毒活疫苗将在对抗成人肺结核和原发性疾病方面发挥重要作用。