EXPRESSION OF TUBERCULOSIS IN THE LUNG

肺泡巨噬细胞是细胞防御的第一道防线 吸入的传染病，如结核分枝杆菌。然而，几乎什么都不知道。 健康人或结核病患者AM摄取和抑制 结核分枝杆菌的生长。我们的初步数据表明效应器的功能 AM对无毒结核杆菌的作用部分超过了单核细胞(MN) 由于肿瘤坏死因子-α(TNF)的释放增加， 作为巨噬细胞激活因子(MAF)。相比之下，AM比较弱 转化生长因子β(TGFbeta)的生产者，一种失活的 细胞因子。然而，结核肉芽肿中的单核巨噬细胞， 表达转化生长因子β，结核患者的MN也是如此。健康受试者的AM是 为抗结核杆菌的效应器功能做好准备，但结核病可能与 释放失活的细胞因子，如转化生长因子β。我来自Healthy 受试者非特异性抑制T淋巴细胞对抗原性和 有丝分裂刺激。在结核病期间，MN特异性地抑制T细胞反应 对结核菌素纯化蛋白衍生物(PPD)可能通过 增加了免疫抑制的转化生长因子β。也是在结核病期间，外周 外周血单个核细胞(PBMC)对分泌的30kD无反应 结核分枝杆菌的抗原(α-Ag)；因为α-Ag是对结核杆菌的直接刺激 MN产生细胞因子，这种无反应可能是由于细胞因子- MN诱导的抑制作用。这些考虑使我们得出这样的假设 在结核病中，AM特异性地抑制T细胞对PPD的反应 (和阿尔法银牌)，并被停用，以通过 转化生长因子β等细胞因子表达增加。在一起，并且 另外，免疫抑制和效应器功能下降也是原因之一。 对肺结核病的发病机制有一定的影响。结核病困扰艾滋病毒感染者 在他们病程的早期，虽然结核菌素皮肤测试仍然是阳性的 CD4‘计数相对完整，表明效应器中的干扰 抗结核分枝杆菌的功能可能是有效的。我们假设这些AM是 灭活基因表达增加导致结核分枝杆菌杀伤缺陷 覆盖MAF的细胞因子。Th1型细胞因子在体内具有保护性作用 某些动物模型。我们假设在结核肉芽肿中，巨噬细胞 表达失活的细胞因子，如转化生长因子β和T细胞 以最佳方式表达Th1型细胞因子。在结核病肉芽肿中来自 HIV感染者，细胞结构被扭曲， T细胞产生的Th1型细胞因子进一步减少；同时 单核吞噬细胞产生失活的细胞因子导致 肉芽肿内黄曲霉毒素载量的不可避免的增加。具体的 旨在验证这些假设的是：L。检验免疫抑制 肺心病患者AM活性及其抑制介质的研究 结核对结核菌素PPD和α-银的血液T细胞反应；以及 比较肺泡和血液淋巴细胞对这些刺激的反应性 包括Th1和Th2细胞因子的产生以及它们各自的 抗原致敏和结核分枝杆菌感染AM的细胞毒性2.评估 结核病人AM中结核分枝杆菌强毒株细胞内生长的研究 巨噬细胞激活和失活的产生及其反应 细胞因子；以及艾滋病毒感染的调节作用。3.至 描述细胞结构和细胞因子的模式 有无结核患者肺肉芽肿中的表达 使用免疫荧光、RNA聚合酶链式反应 原位杂交和免疫组织化学染色。

Alveolar Macrophages (AM) are the first line of cellular defense against inhaled infectious agents such as MTB. Yet almost nothing is known about the capacity of AM from healthy or TB patients to ingest and inhibit the growth of MTB. Our preliminary data indicate that the effector function of AM for avirulent MTB exceeds that of blood monocytes (MN), in part because of increased release of tumor necrosis factor-alpha (TNF) which serves as a macrophage activating factor (MAF). By contrast, AM are weak producers of transforming growth factor beta (TGFbeta), a deactivating cytokine. Mononuclear phagocytes in tuberculous granulomas, however, express TGFbeta, as do MN from TB patients. AM from healthy subjects are primed for effector function against MTB, but TB may be associated with release of deactivating cytokines such as TGFbeta. AM from healthy subjects nonspecifically suppress T lymphocyte responses to antigenic and mitogenic stimuli. During TB, MN specifically suppress T cell responses to tuberculin purified protein derivative (PPD) possibly through increased TGFbeta which is immunosuppressive. Also during TB, peripheral blood mononuclear cells (PBMC) are non responsive to the secreted 30 kD antigen (alpha ag) of MTB; as the alpha ag is a direct stimulus for cytokine production by MN, this unresponsiveness may be due to cytokine- induced suppression by MN. These considerations lead us to the hypothesis that in TB, AM are specifically suppressive of T cell responses to PPD (and the alpha ag) and deactivated for killing of the organism through increased expression of cytokines such as TGFbeta. Together, and separately, immunosuppression and decreased effector function contribute to the pathogenesis of TB in the lung. TB afflicts HIV-infected persons early in their course while tuberculin skin tests are still positive and CD4'counts relatively intact suggesting that disturbances in effector function against MTB may be operant. We hypothesize that these AM are defective in killing of MTB due to increased expression of deactivating cytokines which override MAFs. Th1-type cytokines are protective in certain animal models. We hypothesize that in TB granulomas, macrophages express deactivating cytokines such as TGFbeta and T cells fail to optimally express a Th1-type pattern of cytokines. In TB granulomas from HIV-infected persons, the cellular architecture is distorted with a further decrease in Th1-type cytokines produced by T cells; concurrent production of deactivating cytokines by mononuclear phagocytes leads to an inexorable increase in load of AFB within granulomas. The Specific Aims to test these hypotheses are: l. To examine the immunosuppressive activity and mediators of suppression of AM from patients with pulmonary TB for blood T cell responses to tuberculin PPD and the alpha ag; and to compare alveolar and blood lymphocyte responsiveness to these stimuli including production of Th1 and Th2 cytokines, and their respective cytotoxicity for antigen-pulsed and MTB-infected AM. 2. To assess the intracellular growth of virulent MTB in AM from patients with TB; their production of and response to macrophage activating and deactivating cytokines; and the modulatory effects of HIV infection. 3. To characterize the cellular architecture and the pattern of cytokine expression in pulmonary granulomas from patients with TB with or without HIV using the complementary approaches of immunofluorescence, RNA PCR, in situ hybridization, and immunohistochemistry.