HIV and CD16+ monocytes as cellular reservoir & HIV/pulmonary hypertension

人类免疫缺陷病毒1型（HIV-1）感染患者肺部病毒复制和进化的动力学仍然知之甚少。此外，尽管高效抗逆转录病毒疗法（HAART）取得了无可置疑的成功，但肺部并发症仍然普遍存在。HIV-1在感染的急性期在外周血和终末器官中广泛复制。经过血清转化和HAART抑制HIV病毒载量后，患者可能会经历一个亚临床病毒血症阶段（HIV残留复制）。这一阶段是指病毒在检测水平以下复制的阶段。在这一阶段，组织可能会被周围血浆中不一定检测到的准种重新播种。几个解剖部位为病毒复制和进化提供了受保护的区室；这些可能是亚临床病毒血症的重要来源。这些隔室包括大脑、肠道相关淋巴组织、骨髓和生殖道等。目前的研究重点是在HIV残留复制过程中寻找淋巴细胞以外的细胞储存库。有证据表明骨髓细胞是病毒的细胞储存库，而不是从血浆病毒中重新播种。与普通人群相比，HIV阳性患者更常被诊断为HIV相关性肺动脉高压（HRPAH），无论是否采用抑制性HAART治疗。HRPAH是一种具有明显炎症成分的疾病，也与较高的死亡率有关。我们的研究小组已经证明HIV- Nef与shiv - Nef感染的猕猴肺部血管重塑和管腔闭塞性pah样病变有关。值得注意的是，这些病变只出现在肺部（没有出现在其他器官），并且在炎症浸润之前。其他研究也表明HIV包膜（Env）糖蛋白120也能诱导血管重构。此外，我们有证据表明，诊断为真正HRPAH的患者外周血中含有特定的网状等位基因。HRPAH患者是否只携带Nef标记HIV准种，或者携带env等基因协同进化，目前尚不清楚。HIV的细胞来源及其对接受抑制性HAART治疗的HRPAH患者肺血管的影响也有待阐明。申请人和其他人已经证明，在抑制性HAART期间，典型的CD14+单核细胞不携带HIV，外周血中的CD16+炎性单核细胞携带的病毒准种不同于病毒血症患者血浆中的病毒准种。外周血CD16+单核细胞类似肺泡巨噬细胞，感染HIV后发生跨内皮迁移。鉴于这些有趣的观察结果，我们认为HRPAH患者与HRPAH准种相关。HIV感染患者的外周血CD16+单核细胞充当这些特定HIV准种的特洛伊木马。在到达肺部并被激活后，这些促炎的肺单核细胞/巨噬细胞将这些病毒粒子重新植入肺部，开始恶性循环，编码的Nef和Env增加了可能影响内皮细胞的炎症分子的产生。随后，损伤的内皮细胞可能转变为增殖性血管生成表型，导致HRPAH的临床表现。我们将使用几种实验室技术，单基因组扩增，系统发育分析，使用磁珠分离细胞，荧光杂交和体内细胞成像。

The dynamics of viral replication and evolution in the lungs of patients infected with Human Immunodeficiency Virus type-1 (HIV-1) remain poorly understood. In addition, pulmonary complications are still prevalent despite the unquestioned success of Highly Active Antiretroviral Therapy (HAART). HIV-1 replicates extensively during the acute phase of infection in peripheral blood and end organs. After seroconversion, and suppression of HIV viral loads by HAART, patients may undergo a phase of sub-clinical viremia (HIV residual replication). This phase refers to a stage in which the virus replicates below the levels of detection. During this phase, tissues may be reseeded with quasispecies that are not necessarily detected in the peripheral plasma. Several anatomical sites provide HIV with protected compartments for viral replication and evolution; these may be important sources for the sub-clinical viremia. These compartments include the brain, gut-associated lymphoid tissue, bone marrow, and genital tract, etc. Research efforts are now focused on the search for cellular reservoirs other than lymphocytes during the residual replication of HIV. Evidence points to myeloid cells as the cellular reservoirs of virus not reseeded from plasma viruses. HIV+ patients are more frequently diagnosed with HIV-related pulmonary hypertension (HRPAH) compared to the general population, regardless of suppressive HAART. HRPAH is a disease with a prominent inflammatory component that is also linked to higher mortality. Our group has demonstrated that HIV Nef is associated with vascular remodeling and lumen- obliterative PAH-like lesions in the lungs of SHIV-nef-infected macaques. Of note, these lesions appeared only in the lungs (not in other organs) and were preceded by inflammatory infiltrates. Others have also shown that HIV Envelope (Env) glycoprotein 120 induces vascular remodeling as well. Furthermore, we have evidence that patients diagnosed with bona fide HRPAH harbor specific nef alleles in the peripheral blood. Whether HRPAH patients harbor only a signature Nef or signature HIV quasispecies with genes like env evolving in concert remains unknown at this time. The cellular sources of HIV and their impact in the lung vasculature of HRPAH patients receiving suppressive HAART also remain to be elucidated. The applicant and others have shown that classic CD14+ monocytes do not carry HIV during suppressive HAART and CD16+ pro- inflammatory monocytes in peripheral blood harbor viral quasispecies different from those in plasma of viremic patients. Peripheral blood CD16+ monocytes resemble alveolar macrophages, and undergo transendothelial migration when infected with HIV. Given these intriguing observations, we think that HRPAH patients HRPAH- associated quasispecies. Peripheral blood CD16+ monocytes in HIV-infected patients serve as Trojan horses for these specific HIV quasispecies. After reaching the lung and upon activation, these pro-inflammatory lung monocyte/macrophages reseed the lung with such virions, starting a vicious cycle in which encoded Nef and Env increase the production of inflammatory molecules that may impact endothelial cells. Subsequently, injured endothelial cells may switch to a proliferative-angiogenic phenotype leading to the clinical picture of HRPAH. We will use several laboratory techniques single-genome amplification, phylogenetic analyses, cell isolation using magnetic beads, fluorescent in itu hybridization and in vivo cell imaging.