Inflammatory mechanisms associated with HIV-1 dementia

描述（由申请人提供）：HIV-1相关痴呆（HAD）部分是由于病毒蛋白异常激活脑内巨噬细胞和小胶质细胞，导致神经元功能障碍和死亡。我们假设小胶质细胞和脑微血管内皮细胞（BMVEC）中的CD40信号可能与候选HIV-1神经毒素（如Tat或血小板活化因子（PAF））的作用协同，并在HAD中发挥关键作用。我们将在三个具体目标中对此进行研究。在Aim 1中，我们将分析候选HIV-1神经毒素和CD40参与对人巨噬细胞和小胶质细胞炎症基因表达的协同作用，通过检查与CD40参与相关的信号机制，包括NF-KB抑制剂、米诺环素和格列酮的抗炎作用分析。在Aim 2中，我们将通过确定导致人类BMVEC中粘附和炎症分子表达增加的特定信号事件，研究CD40参与单核细胞粘附和通过人工血脑屏障迁移以响应HIV-1神经毒素的作用。此外，我们将确定CD40特异性RNA干扰或暴露于药物抑制剂（他汀类药物）后CD40表达的下调是否会拮抗通过血脑屏障的细胞迁移。最后，在Aim 3中，我们将使用CD40- KO小鼠、CD40L KO小鼠或野生型小鼠，用小鼠CD40L特异性单克隆抗体处理，破坏CD40-CD40L相互作用，研究CD40-和HIV-1神经毒素介导的信号传导之间的相互作用是否也有助于CMS炎症和体内突触传递受损。总的来说，这些研究将确定新的治疗策略，可以提高神经艾滋病患者的神经元功能和存活率。

DESCRIPTION (provided by applicant): HIV-1 associated dementia (HAD) is due in part to aberrant activation of brain resident macrophages and microglial cells by viral proteins, causing neuronal dysfunction and death over time. We hypothesize that CD40 signaling in microglia and in brain microvascular endothelial cells (BMVEC) may synergize with the effects of candidate HIV-1 neurotoxins, such as Tat or platelet activating factor (PAF), and play a pivotal role in HAD. We will investigate this in three specific aims. In Aim 1, we will analyze synergistic effects of candidate HIV-1 neurotoxins and CD40 engagement on inflammatory gene expression in human macrophages and microglial cells, by examining signaling mechanisms associated with CD40 engagement, including analyses of the anti- inflammatory effects of NF-KB inhibitors, minocycline and glitazones. In Aim 2, we will examine the role of CD40 engagement in monocyte adhesion and migration through an artificial BBB in response to HIV-1 neurotoxins, by determining specific signaling events that lead to increased expression of adhesion and inflammatory molecules in human BMVEC. Additionally, we will determine whether down-modulation of CD40 expression, following CD40-specific RNA interference or exposure to pharamcologic inhibitors (statins), antagonizes cellular migration through BBB. Finally, in Aim 3, we will use CD40 KO mice, CD40L KO mice or wild-type mice treated with a monoclonal antibody specific for mouse CD40L that disrupts CD40-CD40L interaction, to investigate whether the interplay between CD40- and HIV-1 neurotoxin-mediated signaling also contributes to the CMS inflammation and impaired synaptic transmission in vivo. Collectively, these investigations will identify novel therapeutic strategies that may enhance neuronal function and survival in neuroAIDS.