Mechanisms of dopamine mediated increase in HIV infection of macrophages

 描述（由申请人提供）： 全世界约有3 500万人感染艾滋病毒。HIV在初次感染后很快进入中枢神经系统（CNS），主要感染巨噬细胞。感染的细胞产生新的病毒，并作为CNS内的病毒储存库，使HIV能够逃脱组合抗逆转录病毒疗法（cART）的影响。受感染的巨噬细胞还释放神经毒性因子，这些因子有助于神经炎症和HIV相关神经认知障碍（HAND）的发展。HIV+药物滥用者特别容易受到HIV相关神经发病机制加速发展的影响，全世界超过10%的HIV+个体滥用药物。非法药物导致HIV相关CNS损伤的机制尚不清楚，但所有成瘾物质都会增加CNS中的细胞外多巴胺。我们发现多巴胺通过增加病毒进入这些细胞来增加HIV在人类巨噬细胞中的复制。由于大多数类型的药物滥用，增加HIV进入的多巴胺浓度存在于CNS中，表明HIV感染的药物滥用者中的CNS巨噬细胞暴露于升高的多巴胺。因此，一旦病毒进入大脑，药物滥用可能会增加HIV进入巨噬细胞，迅速扩大CNS储库的大小并加速HAND的发展。在cART开始前接种CNS，即使在cART期间，CNS中也可能持续存在低水平病毒复制。此外，HIV+药物滥用者对cART的依从性较差，在治疗中断期间使用药物可能会显著增强病毒反弹的影响。因此，了解多巴胺对巨噬细胞HIV感染的影响对于治疗HIV+药物滥用者至关重要，即使在cART时代也是如此。该提案将使用体外系统和多巴胺升高存在下的急性CNS感染灵长类动物模型来解决这个问题。我们的体外研究将精确地描述多巴胺增加HIV进入的机制，这表明新的靶点可以作为新的进入抑制剂或治疗策略的基础。灵长类动物模型将证明多巴胺在体内急性CNS感染中的影响，并提供一个框架，在其中检查多巴胺受体拮抗剂与暴露前预防（PrEP）方案的使用，或作为辅助治疗与cART一起在HIV+药物滥用者或其他使用影响多巴胺能系统的治疗剂的人中给药。该系统还将表征多巴胺对CNS感染和神经免疫反应的影响，为临床医生在HIV+个体中使用多巴胺能药物提供禁忌症数据。

 DESCRIPTION (provided by applicant): Approximately 35 million people are infected with HIV worldwide. HIV enters the central nervous system (CNS) soon after initial infection, infecting primarily macrophages. Infected cells produce new virus and act as viral reservoirs within the CNS, enabling HIV to escape the effects of combinatorial anti-retroviral therapy (cART). Infected macrophages also release neurotoxic factors that contribute to the development of neuroinflammation and HIV-associated neurocognitive disorders (HAND). HIV+ drug abusers are especially vulnerable to the accelerated development of HIV-associated neuropathogenesis, and more than 10% of HIV+ individuals around the world abuse drugs. The mechanisms by which illicit drugs contribute to HIV-associated CNS damage are unclear, but all addictive substances increase extracellular dopamine in the CNS. We showed dopamine increases HIV replication in human macrophages by increasing the entry of the virus into these cells. The dopamine concentration that increases HIV entry is present in the CNS as a result of most types of drug abuse, indicating that CNS macrophages in HIV infected drug abusers are exposed to elevated dopamine. Thus, drug abuse could increase HIV entry into macrophages as soon as the virus enters the brain, rapidly expanding the size of the CNS reservoir and accelerating the development of HAND. The CNS is seeded before the initiation of cART, and even during cART low-level viral replication can persist in the CNS. Additionally, HIV+ drug abusers have poor adherence to cART and drug use during a break from therapy could significantly enhance the impact of the viral rebound. Thus, understanding the impact of dopamine on HIV infection of macrophages is essential to treatment of HIV+ drug abusers, even in the era of cART. This proposal will address this issue using both in vitro systems and a primate model of acute CNS infection in the presence of elevated dopamine. Our in vitro studies will precisely characterize the mechanism(s) by which dopamine increases HIV entry, suggesting new targets to be exploited as the basis for novel entry inhibitors or therapeutic strategies. The primate model will demonstrate the impact of dopamine in acute CNS infection in vivo, and provide a scaffold in which to examine the use of dopamine receptor antagonists with pre-exposure prophylaxis (PrEP) regimens, or as adjuvant therapy to be administered with cART in HIV+ drug abusers or others using therapeutics which affect the dopaminergic system. This system will also characterize the impact of dopamine on CNS infection and the neuroimmune response, providing contraindication data for clinicians using dopaminergic drugs in HIV+ individuals.