HIV-Human Peritonal Macrophage Interactions

描述（由申请人提供）：巨噬细胞是HIV既能有效复制又能以潜伏状态持续存在的主要细胞类型之一，在HIV发病机制中起着至关重要的作用。与CD 4 + T细胞相反，巨噬细胞对HIV诱导的杀伤具有抗性，并且寿命长。事实上，巨噬细胞似乎是一个重要的储库，并在AIDS患者和高致病性SHIV感染的恒河猴中在CD 4 + T细胞耗尽后维持高病毒载量。重要的是，巨噬细胞是机会性感染期间HIV的主要来源，机会性感染在AIDS的晚期阶段更频繁地发生。由于长期存在的HIV储库构成了根除HIV的主要障碍，因此了解HIV-巨噬细胞相互作用的细胞和分子机制对于开发针对HIV和AIDS流行病的新型有效治疗策略至关重要。 原代巨噬细胞对HIV的易感性取决于细胞的解剖位置和激活状态。HIV-1和巨噬细胞之间相互作用的实验研究一直受到难以分离大量人原代巨噬细胞的阻碍。我们最近发现，腹腔巨噬细胞（PMs）是非常丰富的腹水肝硬化患者和易受HIV-1感染。这些细胞在体外寿命长，可以冷冻保存。新鲜分离的PM对HIV R5、X4、X4 R5原代分离株不敏感，但对X4-T细胞系适应株（TCLA）不敏感。有趣的是，在培养7天后，PM获得了对X4-TCLA菌株的易感性，并产生了比新鲜分离的PM更大量的原发性X4和X4 R5 HIV。同时，CXCR 4 mRNA水平和CC-趋化因子的产生在培养7天期间显著增加，这表明HIV-辅助受体和CC-趋化因子水平的增加可能分别有助于对X4-TCLA的易感性和X4-利用分离株的病毒产生的增强。 当巨噬细胞是HIV的主要来源时，HIV辅助受体从R5到X4的转换与快速的CD 4 + T细胞损失和AIDS的进展有关。尽管HIV共受体转换的基础归因于病毒群体与免疫系统的各种细胞群体的复杂相互作用，但巨噬细胞对HIV共受体转换的贡献尚不清楚。我们的长期目标是确定巨噬细胞是否作为一个重要的水库，以及它们是否在疾病进展的晚期在HIV辅助受体转换中发挥作用。因此，HIV-腹腔巨噬细胞相互作用的进一步表征将为巨噬细胞在HIV发病机制中的作用提供重要的见解。 该提案的目标是剖析PM中动态HIV共受体使用的潜在机制，并扩增和表征HIV感染个体的腹腔巨噬细胞的HIV包膜。这项研究的结果将提高我们对巨噬细胞在HIV发病机制中的作用的理解，并可能促进新的治疗方法的发现。 公共卫生相关性：该提案的目标是剖析PM中动态HIV共受体使用的潜在机制，并表征HIV感染患者PM中的HIV Env。

DESCRIPTION (provided by applicant): Macrophages, one of the major cell types in which HIV can both productively replicate and persist in a latent state, play a crucial role in HIV pathogenesis. In contrast to CD4+ T cells, macrophages are resistant to HIV-induced killing and have long lifespan. Indeed, macrophages appear to be an important reservoir and sustain high virus loads after depletion of CD4+ T cells in AIDS patients and in highly pathogenic SHIV- infected rhesus macaques. Importantly, macrophages are the major source of HIV during opportunistic infections, which occur more frequently during the advanced stages of AIDS. Because the long-lived HIV reservoirs constitute a major obstacle to HIV eradication, understanding the cellular and molecular mechanisms underlying HIV-macrophage interactions is vital for developing novel and efficacious therapeutic strategies against HIV and the AIDS epidemic. Susceptibility of primary macrophages to HIV depends on the anatomical location and activation state of the cells. Experimental investigation of the interactions between HIV-1 and macrophages has been impeded by the difficulty of isolating a large amount of human primary macrophages. We recently demonstrate that peritoneal macrophages (PMs) are highly abundant in ascitic fluid of patients with cirrhosis and are susceptible to HIV-1 infection. These cells are long-lived in vitro and can be cryopreserved. Freshly isolated PMs are susceptible to HIV R5, X4, X4R5 primary isolates by not but not to X4-T cell line adapted (TCLA) strains. Interestingly, after 7 days in culture, PMs acquired susceptibility to X4-TCLA strains and produced greater amounts of primary X4 and X4R5 HIV than freshly-isolated PMs. Concurrently, the level of CXCR4 mRNA and production of CC-chemokines increased significantly during 7 days in culture, suggesting that an increase in levels of HIV-coreceptors and CC-chemokines may contribute to the susceptibility to X4-TCLA and enhanced viral production of X4-ultizing isolates, respectively. HIV coreceptor switch from R5 to X4 has been associated with rapid CD4+ T cell loss and progression of AIDS when macrophages are the major source of HIV. Although the basis for HIV co-receptor switch is attributed to the complex interaction of the viral population with various cell populations of the immune system, the contribution by macrophages to HIV co-receptor switch is not known. Our long-term goal is to determine whether macrophages serve as an important reservoir and whether they play a role in HIV-coreceptor switch at the late stage of disease progression. Thus, further characterization of HIV-peritoneal macrophage interactions will offer an important insight into the role of macrophages in HIV pathogenesis. The goal of this proposal is to dissect the underlying mechanisms of dynamic HIV co-receptor usages in PMs and to amplify and characterize HIV envelopes from peritoneal macrophages from HIV-infected individuals. The outcome of this study will enhance our understanding of the role of macrophages in HIV pathogenesis and may facilitate discoveries of new ways for treatment. PUBLIC HEALTH RELEVANCE: The goal of this proposal is to dissect the underlying mechanisms of dynamic HIV co-receptor usages in PMs and to characterize HIV Env in PMs from HIV-infected patients.