Modulation of Cystatins and Cathepsins in HIV-1 Neuropathogenesis

描述（由申请人提供）：尽管抗逆转录病毒治疗（HAART），认知障碍（CI）仍发生在晚期HIV-1感染期间。神经元损伤的分子和细胞机制是从单核吞噬细胞（MP；血管周围巨噬细胞和小胶质细胞）产生的神经毒性分泌产物演变而来的。尽管影响毒性MP分泌的细胞内机制尚不完全清楚，但效应细胞反应确实在CI中起关键作用。该研究的长期目标是更好地了解巨噬细胞分泌因子在大脑进行性HIV感染过程中的稳态控制作用，并发现潜在治疗的新靶点。在许多分泌因子中，MP分泌的胱抑素和组织蛋白酶在神经调节反应中发挥着广泛而重要的作用。特别是，我们的实验室和离体实验通过蛋白质组学分析显示，在hiv血清阳性的CI妇女的病毒感染的MP培养液和脑脊液（CSF）中存在组织蛋白酶、胱抑素和SOD。然而，它们在神经退行性过程中的作用尚不完全清楚。本研究将阐明胱抑素、组织蛋白酶和SOD在hiv感染的巨噬细胞及其与神经元细胞的相互作用中所起的作用，这对于在CI诱导过程中控制脑内促炎微环境至关重要。我们假设，氧化应激期间感染hiv的巨噬细胞中胱抑素的失调促进了组织蛋白酶b诱导的神经毒性，因此有助于CI。我们将通过以下具体目的来验证这一假设：1)通过分析基因和蛋白表达，确定胱抑素B和组织蛋白酶B之间的相互作用如何调节巨噬细胞中的HIV-1感染并影响神经毒性表型；2)定义在Aim 1中发现的胱抑素B/C、组织蛋白酶B、SOD和受其解除管制影响的蛋白作为HAART存在下CI进展的预测因子的作用。本研究的意义和长期意义在于，它将填补巨噬细胞中胱他汀、组织蛋白酶和SOD相互作用及其在神经发病机制中的作用方面的知识空白。西班牙队列的研究也将阐明半胱氨酸抑制素、组织蛋白酶和超氧化物歧化酶在haart后时代hiv认知障碍中的作用。拟议的研究将确定巨噬细胞胱抑素、组织蛋白酶、SOD和受其解除管制影响的蛋白质在HIV复制和神经毒性中的作用。在HAART时代，以认知功能和抗病毒治疗为特征的西班牙裔艾滋病毒感染妇女队列是研究这些可能的生物标志物的极好来源。来自该队列的脑脊液、血浆、单核细胞和巨噬细胞样本已被纵向储存，并为验证我们的假设提供了重要来源：在hiv感染的巨噬细胞中，胱他汀类药物的过度表达将促进组织蛋白酶b诱导的神经毒性，从而促进CI。本研究可能为诊断和治疗提供新的靶点。

DESCRIPTION (provided by applicant): Modulation of cystatins and cathepsins in the neuropathogenesis of HIV-1 infection Cognitive impairment (CI) occurs during advanced HIV-1 infection, despite antiretroviral therapy (HAART). The molecular and cellular mechanisms for neuronal impairment evolve from neurotoxic secretory products produced from mononuclear phagocytes (MP; perivascular macrophages and microglia). Although the intracellular mechanisms that affect toxic MP secretions are incompletely known, the effector cell responses do play a pivotal role in CI. The long-term goal of the proposed study is to provide a better understanding of the role of macrophage secretory factors in homeostatic control during progressive HIV infection of the brain and to uncover novel targets for potential therapies. Among many secretory factors, cystatins and cathepsins secreted by MP play broad yet important roles in neuroregulatory responses. In particular, our laboratory and ex vivo experiments have shown the presence of cathepsins, cystatins, and SOD in virus-infected MP culture fluids and cerebrospinal fluid (CSF) of HIV-seropositive women with CI by proteomic analyses. Nevertheless, their role in neurodegenerative processes is not completely understood. The proposed study will elucidate the role played by cystatins and cathepsins, and SOD, on HIV-infected macrophages and their interactions with neuronal cells, which is critical for controlling the pro-inflammatory microenvironment in the brain during the induction of CI. We hypothesize that dysregulation of cystatins in HIV-infected macrophages during oxidative stress promotes cathepsin-B induced neurotoxicity and therefore contributes to CI. We will test this hypothesis with the following specific aims: 1) To determine, by analysis of gene and protein expression, how the interplay between cystatin B and cathepsin B regulates HIV-1 infection in macrophages and affects neurotoxic phenotype; 2) To define the roles of cystatin B/C, cathepsin B, SOD, and proteins affected by their deregulation, found in Aim 1, as predictors of progression to CI in the presence of HAART. The significance and long-term implication of this study is that it will fill the gaps in knowledge regarding the interactions between cystatins, cathepsins and SOD in macrophages and their role in neuropathogenesis. The studies with the Hispanic cohort will also clarify the role of cystatins, cathepsins, and SOD in HIV-cognitive impairment in the post-HAART era. The proposed studies will determine the role of macrophage cystatins, cathepsins, SOD, and the proteins affected by their deregulation in HIV replication and neurotoxicity. The Hispanic cohort of HIV-infected women characterized for cognitive function and under antiviral therapy is an excellent source for the study of these possible biomarkers in the HAART era. The CSF, plasma, monocyte, and macrophage samples derived from this cohort have been stored longitudinally and provide an important source for testing our hypothesis: that over expression of cystatins in HIV-infected macrophages will promote cathepsin B-induced neurotoxicity and therefore contribute to CI. This study may elucidate novel targets for diagnosis and therapy.