EXPRESSION OF TUBERCULOSIS IN THE LUNG

肺泡巨噬细胞（AM）是细胞防御的第一道防线， 吸入的感染因子，如MTB。然而，几乎没有人知道 来自健康或结核病患者的AM摄取和抑制 山地车的增长。我们的初步数据表明， AM对无毒力MTB的作用超过了血液单核细胞（MN）， 因为肿瘤坏死因子-α（TNF）的释放增加， 作为巨噬细胞活化因子（MAF）。相比之下，AM较弱 转化生长因子β（TGF β）的生产者，一种失活的 细胞因子然而，结核性肉芽肿中的单核吞噬细胞， 表达TGF β，结核病患者的MN也是如此。来自健康受试者的AM是 针对MTB的效应子功能，但TB可能与 释放失活细胞因子如TGF β。来自健康 受试者非特异性抑制T淋巴细胞对抗原和 促有丝分裂刺激在TB期间，MN特异性抑制T细胞应答 结核菌素纯蛋白衍生物（PPD）可能通过 增加了TGF β，这是免疫抑制。此外，在TB期间， 血液单核细胞（PBMC）对分泌的30 kD MTB的抗原（α ag）;因为α ag是MTB的直接刺激物， MN产生细胞因子，这种无反应性可能是由于细胞因子- 由MN引起的抑制。这些考虑使我们得出这样的假设： 在TB中，AM特异性抑制T细胞对PPD应答 (andα Ag），并通过以下途径使其失活以杀死生物体 细胞因子如TGF β的表达增加。一起 免疫抑制和效应器功能降低分别导致 肺结核的发病机制结核病折磨艾滋病毒感染者 在结核菌素皮肤试验仍呈阳性时， CD 4 '计数相对完整，表明效应细胞中的干扰 对MTB的功能可能是操作性的。我们假设这些AM是 由于失活基因的表达增加， 这些细胞因子会覆盖MAF。Th 1型细胞因子在 某些动物模型。我们假设在结核肉芽肿中，巨噬细胞 表达失活细胞因子如TGF β和T细胞不能 最佳地表达Th 1型细胞因子模式。在结核肉芽肿中， 艾滋病毒感染者，细胞结构被扭曲， T细胞产生的Th 1型细胞因子进一步减少;同时 单核吞噬细胞产生的灭活细胞因子导致 肉芽肿内AFB负荷的不可阻挡的增加。具体 测试这些假设的目的是：l。检查免疫抑制剂 肺结核患者AM活性及抑制AM的介质 TB用于血液T细胞对结核菌素PPD和α ag的反应;以及 比较肺泡和血液淋巴细胞对这些刺激的反应性 包括Th 1和Th 2细胞因子的产生，以及它们各自的 抗原脉冲和MTB感染的AM的细胞毒性。2.评估 结核病患者AM中毒性MTB细胞内生长; 巨噬细胞激活和失活的产生和应答 细胞因子;以及HIV感染的调节作用。3.到 表征细胞结构和细胞因子的模式 在肺结核患者的肺肉芽肿中的表达 使用免疫荧光，RNA PCR， 原位杂交和免疫组织化学。

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.