Role Of Monocytes In AIDS And As Targets For Antiviral T

该项目旨在了解HIV-1结合，进入，复制和组装的机制，特别是在巨噬细胞中，并制定有效的策略来预防和/或抑制感染。HIV-1感染的后果是免疫缺陷，使宿主易于机会性感染。反过来，机会性感染影响靶细胞对HIV-1感染和复制的易感性。利用M.作为模型共病原体，我们定义了多种病毒允许因子。此外，免疫激活通常发生在扁桃体和非感染性粘膜炎性病变中，也可能与病毒复制的近端位点相关。这些激活/炎症和增强HIV-1感染之间的联系保证了进一步阐明促进对HIV-1的宽容的因素。在体外模型中感染人巨噬细胞，通过cDNA微阵列分析揭示了信号转导、立即早期基因表达和与病毒复制相关的下游基因的模式。随着信号级联、基因转录和巨噬细胞特异性病毒动力学之间的关联被阐明，我们的目标是确定新的细胞靶点来干扰HIV复制。在这方面，在HIV-1感染的巨噬细胞中持续上调的基因之一是分化标志物和细胞周期调节因子，其似乎受到病毒的影响，并且是其最佳复制所必需的。 与CD 4+淋巴细胞相反，HIV-1感染的巨噬细胞通常抵抗细胞死亡，支持病毒复制，从而促进HIV-1传播。多种因素可能有利于巨噬细胞作为一个有弹性的主机，不仅支持HIV-1的感染，而且还促进复制和持久性的灵长类逆转录病毒的慢病毒亚科的这个成员。巨噬细胞与R5病毒在体外的相遇涉及在多个基因的转录调节中发生的信号级联，所述多个基因包括与宿主防御、细胞周期、NFkB调节和细胞凋亡相关的基因。重要的是，增强的基因表达是短暂的，下降到接近控制水平，在这种静止状态下，病毒继续其生命周期畅通无阻。然而，当病毒复制变得突出时，在病毒基因产物的编排下再次发生宿主基因的增加。这种双相宿主反应必须满足寄生病毒的需要，因为病毒复制活性发生并导致细胞内和细胞表面相关的病毒出芽。深入了解HIV-1如何利用宿主因素为病毒复制和传播到新病毒宿主创造一个宽松的环境，可能会为有针对性地中断这一致命过程提供机会。为了阐明病毒如何征用巨噬细胞细胞内机器以获得其益处，通过包括cDNA表达阵列的多个参数分析HIV-1感染的人单核细胞衍生的巨噬细胞的病毒诱导的基因转录。HIV-1感染诱导了与宿主防御、信号转导、凋亡和细胞周期相关的基因的转录调控，其中以细胞周期蛋白依赖性激酶抑制因子1A最为突出。mRNA和蛋白质表达遵循双峰模式，最高水平发生在活跃的HIV-1复制期间。用反义寡核苷酸处理巨噬细胞减少了HIV-1的复制。此外，已知影响激酶抑制剂表达的合成三萜类和过氧化物酶体增殖物激活受体γ配体2-氰基-3，12-二氧代齐墩果烷-1，9-二烯-28-酸（CDDO）抑制病毒复制。这些数据暗示这种宿主细胞分子是病毒复制的关键巨噬细胞促进剂。此外，这种分子的调节剂，如CDDO，可以提供一种干预方法来调节HHIV-1复制。为此，我们获得了一项临床到床边奖，以进行CDDO治疗艾滋病/淋巴瘤的临床试验。

This project is directed at understanding the mechanisms of HIV-1 binding, entry, replication and assembly, particularly in macrophages, and in developing an effective strategy to prevent and/or inhibit infection. Immunodeficiency, the consequence of HIV-1 infection, predisposes the host to opportunistic infections. In turn, opportunistic infections influence target cell susceptibility to HIV-1 infection and replication. Using M. avium as a model co-pathogen, we have defined multiple viral permissive factors. Moreover, immune activation as typicallly occurs in tonsils and non-infectious mucosal inflammatory lesions may also be associated with proximal sites of viral replication. These connections between activation/inflammation and enhancement of HIV-1 infection warrant further elucidation of the factors promoting permissiveness to HIV-1. Infection of human macrophages in an in vitro model revealed a pattern of signal transduction, expression of immediate early genes, and downstream genes associated with viral replication by cDNA microarray analyses. As the association between signaling cascades, gene transcription and macrophage-specific viral dynamics is elucidated, our goal is to identify new cellular targets to interfere with HIV replication. In this regard, one of the genes consistently upregulated in HIV-1 infected macrophages is a differentiation marker and cell cycle regulator, which appears to be influenced by the virus and necessary for its optimal replication. In contrast to CD4+ lymphocytes, HIV-1 infected macrophages typically resist cell death, support viral replication, and consequently facilitate HIV-1 transmission. Multiple contributing factors may favor the macrophage as a resilient host, not only supporting infection by HIV-1, but also promoting replication and persistence of this member of the lentivirus subfamily of primate retroviruses. An encounter between macrophages and R5 virus in vitro engages a signal cascade eventuating in transcriptional regulation of multiple genes including those associated with host defense, cell cycle, NFkB regulation and apoptosis. Importantly, enhanced gene expression is transient, declining to near control levels and during this quiescent state, the virus continues its life cycle unimpeded. However, when viral replication becomes prominent, an increase in host genes again occurs under the orchestration of viral gene products. This biphasic host response must fulfill the needs of the parasitic virus as viral replication activity occurs and leads to intracellular and cell surface associated viral budding. Inroads into understanding how HIV-1 co-opts host factors to generate a permissive environment for viral replication and transmission to new viral hosts may provide opportunities for targeted interruption of this lethal process. To elucidate how the virus commandeers macrophage intracellular machinery for its benefit, HIV-1 infected human monocyte-derived macrophages were analyzed for viral-induced gene transcription by multiple parameters including cDNA expression array. HIV-1 infection induced the transcriptional regulation of genes associated with host defense, signal transduction, apoptosis and cell cycle, of which the cyclin-dependent kinase inhibitor 1A is the most prominent. mRNA and protein expression followed a bimodal pattern with maximum levels occurring during active HIV-1 replication. Treatment of macrophages with anti-sense oligonucleotides reduced HIV-1 replication. Furthermore, a synthetic triterpenoid and peroxisome proliferator-activated receptor gamma ligand, 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid (CDDO), known to influence the kinase inhibitor expression, suppressed viral replication. These data implicate this host cell molecule as a pivotal macrophage facilitator of viral replication. Moreover, regulators of this molecule, such as CDDO, may provide an interventional approach to modulate HHIV-1 replication. To this end, we received a Bench-to-Bedside Award to pursue clinical trials of CDDO in the treatment of AIDS/lymphoma.