Targeting an immunomodulatory protease for adjunctive tuberculosis chemotherapy

 描述(申请人提供)：目前治疗结核病(TB)的方案使用多种抗生素，耗时长且费力，并促成了耐药结核病的出现。因此，通过缩短治疗时间和提高疗效来改进抗结核化疗是全球结核病控制的高度优先事项。操纵宿主免疫反应以减少结核分枝杆菌诱导的免疫反应的有害影响可能会增强抗生素的疗效。我们推测，阻断结核分枝杆菌(Mtb)关键免疫调节酶Hip1的功能，将为体内感染的溶解创造更有利的免疫环境，导致抗生素加速Mtb的清除，缩短治疗时间。靶向病原体特异性毒力因子以改善治疗结果的这一概念以前从未被探索过。我们小组的研究表明，Hip1促进结核分枝杆菌感染的巨噬细胞、树突状细胞和小鼠的有害先天和获得性免疫反应。缺乏Hip1对宿主是有益的，因为这会导致轻微的免疫病理反应，并延长受感染小鼠的存活时间，尽管体内细菌负荷很高。因此，我们认为抑制Hip1对于开发结核病的辅助免疫疗法是有吸引力的。我们将使用结核化疗的C3HeB/FEJ小鼠模型来测试这样的假设，即在抗结核治疗的同时沉默Hip1将减少肺部的病理和组织损伤，并加速结核分枝杆菌的清除。我们建议进行以下概念验证研究：目的1.确定在抗结核小鼠模型中，沉默HIP1是否能提高结核分枝杆菌的清除。我们将用条件Hip1基因敲除菌株感染小鼠，评估抗生素治疗后各时间点的细菌清除情况，并与对照组相比评估复发的发生。目的2.研究化疗期间Hp-1沉默对肺免疫反应和肉芽肿性病变的影响。我们将在治疗前、治疗中和治疗后比较野生型和hip1基因敲除结核分枝杆菌感染引起的炎症反应、抗原特异性T细胞反应和肺肉芽肿病变的性质。这些研究将给我们提供关于抑制Hip1是否是辅助免疫治疗的可行方法的重要见解，并为在体内测试候选Hip1抑制剂提供一个框架。

 DESCRIPTION (provided by applicant): The current regimen for treating tuberculosis (TB) involves multiple antibiotics, is long and arduous and has contributed to the emergence of drug-resistant TB. Improving anti-TB chemotherapy by shortening treatment and enhancing efficacy is therefore a high priority for global TB control. Manipulating the host immune response to reduce the harmful effects of Mtb-induced immune responses may enhance the efficacy of antibiotics. We hypothesize that blocking the functions of a key Mycobacterium tuberculosis (Mtb) immunomodulatory protease, Hip1, will create a more favorable in vivo immune milieu for resolving infection, leading to accelerated clearance of Mtb by antibiotics and shortened treatment. This concept of targeting pathogen-specific virulence factors to improve treatment outcomes has not previously been explored. Studies from our group have shown that Hip1 promotes detrimental innate and adaptive immune responses in Mtb- infected macrophages, dendritic cells and mice. Absence of Hip1 is beneficial to the host as this results in mild immunopathology and prolonged survival of infected mice despite high bacterial burdens in vivo. Thus we propose that inhibiting Hip1 is attractive for developing adjunctive immune therapeutics for TB. We will use the C3HeB/FeJ mouse model of TB chemotherapy to test the hypothesis that silencing hip1 in conjunction with anti-TB treatment will reduce pathology and tissue damage in the lung and accelerate clearance of Mtb. We propose the following proof of concept studies: Aim 1. Determine whether silencing hip1 improves clearance of Mtb during anti-TB chemotherapy in a mouse model of TB. We will infect mice with a conditional hip1 knockdown strain and assess bacterial clearance at time points following antibiotic treatment, and evaluate the occurrence of relapse compared to controls. Aim 2. Characterize the effect of hip1 silencing on lung immune responses and granulomatous pathology during chemotherapy. We will compare inflammatory responses, antigen-specific T cell responses and the nature of lung granuloma lesions induced by infection with wild type and hip1 knockdown Mtb strains before, during and after treatment. These studies will give us important insights into whether inhibition of Hip1 is a feasible approach for adjunctive immune therapy and provide a framework for testing candidate Hip1 inhibitors in vivo.