HIV-1 gp120-induced Endothelial Cell Dysfunction

描述(申请人提供)：人类免疫缺陷病毒(HIV)在感染的早期阶段入侵大脑对于感染晚期的患者来说，中枢神经系统(CNS)功能障碍是常见的致病原因，经常导致进行性痴呆、脑萎缩和死亡。有证据表明，HIV和/或HIV相关蛋白在HIV相关性痴呆(HAD)复合体的发病机制中起关键作用。要阐明HAD的发病机制，了解HIV侵袭大脑的机制是重要的。血脑屏障的破坏在HAD患者中很常见，尽管缺乏有效的HIV感染脑血管内皮细胞。HIV-1包膜蛋白gp120存在于HIV脑炎患者的大脑中，是神经毒性的最新证据，来自我们实验室和其他人的证据表明，gp120对脑内皮细胞有直接影响。我们的假设是gp120直接导致血脑屏障功能障碍，并在病毒侵袭脑中发挥重要作用。为了验证这一假说，我们计划实现以下目标。目的：为了验证HIV-1gp120蛋白对人脑微血管内皮细胞的毒性并直接诱导血脑屏障的破坏和/或破坏的假说，我们将检测内皮细胞的通透性和凋亡率。目的2为了验证gp120蛋白暴露于人脑微血管内皮细胞导致紧密连接蛋白丢失的假说，我们将用免疫印迹和免疫荧光方法检测occludin、Claudia-5和zonula occludens-1的表达。目的3：确定趋化因子受体是否参与gp120诱导的血脑屏障的破坏和/或损伤。目的4：确定gp120诱导的血脑屏障功能障碍的信号转导途径。这些实验的数据将有助于确定gp120在破坏血脑屏障完整性和艾滋病毒入侵大脑中所起的作用，并将提出预防艾滋病毒感染期间gp120介导的脑内皮功能障碍的治疗方法。

DESCRIPTION (provided by applicant): The human immunodeficiency virus (HIV) invades the brain in the early stages of infection For patients in the advanced stage of infection, dysfunction of the central nervous system (CNS) is a common cause of morbidity and often leads to progressive dementia, cerebral atrophy and death. Evidence suggest that HIV and /or HIV-associated proteins are critical to the pathogenesis of the HIV-associated dementia (HAD)complex .To elucidate the pathogenesis of HAD, it is important to understand by what mechanisms HIV invades the brain. Breakdown of the blood-brain barrier is commonly seen in patients with HAD, despite the lack of productive HIV-infection of the brain endothelium. The HIV-1 envelope protein gp120 is present in the brain of patients with HIV encephalitis, and is neurotoxic Recent evidence from our laboratory, and by others, suggests a direct effect of gp120 on the brain endothelium. It is our hypothesis that gp120 directly causes blood-brain barrier dysfunction and plays a major role in viral invasion of the brain To test this hypothesis, we plan the following aims. Aim 1: To test the hypothesis that HIV-1 gp120 proteins are toxic to human brain microvascular endothelial cells and directly induce a disruption and/or damage of the blood-brain barrier we will measure endothelial cell permeability and apoptosis. Aim 2 To test the hypothesis that exposure of gp120 proteins to human brain microvascular endothelial cells result in the loss of tight junction proteins we will assess the expression of occludin, claudia-5 and zonula occludens-1 using western blotting and immunofluorescence. Aim 3: To determine if chemokine receptors are involved in gp120-induced blood-brain barrier disruption and/or damage Aim 4: To determine the signal transduction pathways involved in gp120-induced blood-brain barrier dysfunction. Data from these experiments will help determine the role that gp120 plays in the breach of blood-brain barrier integrity and HIV invasion of the brain, and will suggest therapeutic approaches to preventing gp120-mediated dysfunction of the brain endothelium during HIV infection.