Restoration of alveolar macrophage function in HIV patients: A clinical study.

描述（由申请方提供）：HIV靶向淋巴细胞和巨噬细胞作为宿主细胞。大多数研究将艾滋病的进展仅仅等同于T细胞监视的丧失。然而，有人认为，由于艾滋病毒寄生在巨噬细胞中，因此病毒可能会直接损害吞噬细胞的杀微生物能力。利用新的吞噬体成熟的测定，我们已经证明，艾滋病毒感染减少了吞噬体的水解能力和损害超氧化物的产生。鉴于巨噬细胞作为抵抗微生物入侵的主要屏障的作用，这将产生严重的后果，特别是在粘膜表面如呼吸道。在这项研究中，我们提出了以下三个问题。 1. HIV感染在多大程度上损害了巨噬细胞的抗微生物能力？ 将对HIV感染的PBMC衍生的巨噬细胞进行一组生理学测定，以确定吞噬细胞功能受损的程度，即吞噬体酸化、溶酶体水解酶的获得、活性氧和氮中间体的产生以及HIV感染的细胞限制一组模型细菌病原体生长的能力。 2. HIV感染患者的肺泡巨噬细胞是否表现出类似的吞噬功能破坏？ 在体外验证之后，这些试验将在马拉维伊丽莎白女王医院的艾滋病毒感染患者的支气管肺泡灌洗液细胞上重复进行。此外，将采集样本进行电子显微镜检查和免疫电子显微镜检查，并提取总核酸用于回顾性识别可能的合并感染。 3. HIV是如何损害巨噬细胞功能的？这种损害可以通过化疗逆转吗？ a.我们建议进行功能性研究，以确定HIV如何调节 吞噬体 B.我们将进行高通量筛选，以确定抵消HIV抑制活性的小分子。 C.我们将检测这些化合物逆转HIV感染患者肺泡巨噬细胞吞噬功能抑制的能力。 公共卫生相关性：艾滋病的进展几乎普遍与免疫监视的丧失有关。然而，我们发现HIV感染的巨噬细胞表现出吞噬体功能受损，降低了它们的杀微生物能力，从而直接增加了机会性感染的可能性。在对HIV感染患者肺泡巨噬细胞的前瞻性临床研究中，我们将平行进行体外实验，以探讨逆转HIV介导的巨噬细胞功能抑制的化合物的机制和鉴定。

DESCRIPTION (provided by applicant): HIV targets both lymphocytes and macrophages as host cells. Most studies equate progression to AIDS solely as the loss of T cell surveillance. However, it has been suggested that because HIV parasitizes macrophages, the virus could impair the microbicidal capacity of the phagocyte directly. Exploiting novel assays for phagosomal maturation we have demonstrated that HIV infection diminishes the hydrolytic capacity of the phagosome and impairs superoxide production. Given the macrophage's role as the primary barrier against microbial invasion this will have serious consequences, particularly at mucosal surfaces such as the respiratory tract. In this study we propose to address the following 3 questions. 1. To what extent does HIV infection compromise the anti-microbial capacity of macrophages? HIV-infected, PBMC-derived macrophages will be subjected to a panel of physiological assays to determine the extent to which phagocyte function is impaired i.e. phagosome acidification, the acquisition of lysosomal hydrolases, the generation of reactive oxygen and nitrogen intermediates, and the capacity of the HIV-infected cells to limit growth of a panel of model bacterial pathogens. 2. Do alveolar macrophages from HIV-infected patients demonstrate similar subversion of phagocyte function? Following in vitro validation, these assays will be repeated on broncholavage cells from HIV-infected patients at the Queen Elizabeth Hospital in Malawi. In addition, samples will be acquired for electron microscopy and for immuno-electron microscopy, and total nucleic acid will be extracted for retrospective identification of possible co-infections. 3. How does HIV impair macrophage function and can this be reversed chemotherapeutically? a. We propose functional studies to determine how HIV modulates the microbicidal capacity of the phagosome. b. We will conduct high-throughput screens to identify small molecules that counteract the suppressive activity of HIV. c. We will assay these compounds for their ability to reverse the suppression of phagocyte function in alveolar macrophages from HIV-infected patients. PUBLIC HEALTH RELEVANCE: The progression to AIDS is almost universally correlated with the loss of immune surveillance. However, we have found that HIV-infected macrophages exhibit impaired phagosomal function that reduces their microbicidal capacity, thus directly increasing the likelihood of opportunistic infections. In a prospective clinical study on alveolar macrophages from HIV-infected patients we will parallel our in vitro experiments to pursue both the mechanism and the identification of compounds that reverse the HIV-mediated suppression of macrophage function.