IMMUNOLOGIC CONSEQUENCES OF M. TUBERCULOSIS VIRULENCE

描述（改编自申请人的摘要）： 旨在研究初级和次级线圈的有限保护值， 对空气传播的M.结核 (Mtb)对小鼠将在具有以下特征的小鼠中研究次级应答： 免疫记忆状态，由于感染了 无毒或有毒的活Mtb，然后用化疗治疗， 基本上消除了感染。将接种和未接种疫苗的小鼠 通过气溶胶感染毒性Mtb，并在进行性感染时处死5只小鼠。 感染次数，以跟踪进展和随后的免疫学 控制感染。将处死另外的小鼠以确定 气管支气管引流淋巴结中产生的动力学 Mtb特异性CD4 Th1细胞和CD8 T细胞，通过其 在ELISPOT测定中响应于Ag刺激而分泌IFN γ的能力。 这些T细胞在引流淋巴结中的出现将与 它们出现在血液和肺部感染部位。将 用RNase保护试验和蛋白质印迹法确定， 肺中免疫表达的开始与转录水平相关， 激活介导免疫所需的Th1细胞因子的基因，和 如果感染时巨噬细胞表达免疫需要iNOS， 焦点预测无论是初级免疫还是次级免疫 反应将能够防止感染的建立，即使 非常少量的有毒Mtb，甚至是有毒Mtb，因为 将测试在肺中表达免疫力之前的内在延迟。 预测，一旦表达，免疫力将无法解决，甚至 非常低的感染水平，但会导致感染变得静止， 还将通过用少量结核分枝杆菌攻击小鼠进行测试， 减少化疗病灶中的结核分枝杆菌数量， 表达。延迟表示豁免是否是由于延迟 保护性T细胞的产生，或延迟 感染灶处T细胞外渗所必需的条件， 这些位点将通过过继转移研究进行调查。无法 二次免疫反应，使遗传易感小鼠停止 肺部感染的进展将进行调查。的可能性 基因易感小鼠，将无法阻止致命的再生， 化疗后肺部感染的水平大大降低， 研究了

DESCRIPTION (Adapted from the Applicant's Abstract): The proposed experiments are designed to investigate the limited protective value of the primary and secondary immune responses to airborne infection with virulent M. tuberculosis (Mtb) in mice. The secondary response will be studied in mice that possess a state of immunological memory as a result of having been infected with avirulent or virulent live Mtb and later treated with chemotherapy to essentially abolish infection. Vaccinated and unvaccinated mice will be infected with virulent Mtb by aerosol and 5 mice sacrificed at progressive times of infection to follow the progression and subsequent immunological control of infection. Additional mice will be sacrificed to determine the kinetics of production in the draining tracheobronchial lymph node of Mtb-specific CD4 Th1 cells and CD8 T cells, identified and enumerated by their ability to secrete IFNgamma in response to Ag stimulation in the ELISPOT assay. The appearance of these T cells in the draining nodes will be compared with their appearance in blood and at sites in infection in the lungs. It will be determined, with the RNase protection assay and Western blotting, whether the onset of expression of immunity in the lung is associated with transcriptional activation of genes for Th1 cytokines needed for the mediation of immunity, and if iNOS needed for the expression of immunity by macrophages at infectious foci. The prediction that neither the primary, nor the secondary immune response will be capable of preventing the establishment of infection even with very small numbers of virulent Mtb, or even with a virulent Mtb, because of an intrinsic delay before immunity can be expressed in the lungs will be tested. The prediction that, once expressed, immunity will be unable to resolve even very low levels of infection, but will cause infection to become stationary, will also be tested by challenging mice with small numbers of Mtb, and by later reducing the number of Mtb in lesions with chemotherapy as immunity is being expressed. Whether the delay in expression of immunity is caused by a delay in the production of protective T cells, or a delay in the development of conditions at infectious foci necessary for the extravasation of T cells at these sites will be investigated by adoptive transfer studies. The inability of the secondary immune response to enable genetically susceptible mice to stop lung infection from progressing will be investigated. The possibility that genetically susceptible mice, will be incapable of stopping lethal regrowth of a greatly reduced level of lung infection following chemotherapy will also be investigated.