HIV-Specific T-cells in cerebrospinal fluid (CSF)

描述(申请人提供)：本提案响应PA-01-072，“HIV-1感染中枢神经系统(CNS)”。这项研究有两个主要目标。第一个目标是阐明免疫效应细胞，特别是细胞毒性T细胞(CTL)向中枢神经系统转运的机制，以及这些细胞可能缓解或加剧神经发病的效应功能。第二个目标是确定抗病毒T细胞到脑脊液(CSF)的运输与病毒载量、抗逆转录病毒治疗和神经系统疾病发展之间的关系。在初步研究中，我们确定多参数流式细胞术可用于检测从5-10毫升脑脊液中“体外”获得的抗原特异性CD8+T细胞。在具体目标1中，我们将研究HIV特异性CTL在脑脊液中的频率和转运模式，并确定脑脊液中CTL频率与全身和鞘内免疫激活、趋化因子表达、HIV病毒载量和中枢神经系统疾病发生的关系。在具体目标2中，我们将评估脑脊液CTL的效应功能，包括分泌促炎细胞因子(干扰素-γ、肿瘤坏死因子-α)、细胞溶解效应分子(即穿孔素、颗粒酶)和MHC-I类限制性靶细胞溶解。我们还将评估脑脊液和外周血中HIV特异性CTL的克隆性，并确定这两个群体之间的“重叠”程度。将进行两项研究：第一，对25名外周血中可检测到艾滋病毒特异性CTL的艾滋病毒感染患者进行横断面研究；第二，对40名艾滋病毒感染患者进行纵向研究，其中包括10名停止或中断高效抗逆转录病毒治疗(HAART)的患者，10名开始接受HAART治疗的患者，10名临床稳定的未接受HAART治疗的患者，以及10名有神经系统疾病症状的患者。我们假设，全身淋巴细胞的激活(包括LFA-1和VLA-4的上调)导致激活的淋巴细胞外溢到脑脊液中的增加，并且在中枢神经系统内的病毒复制，随后是局部炎症反应和趋化因子(即IP-10，MIP-1α和MIP-1β，RANTES)的分泌，有助于以非抗原特异性的方式招募表达这些趋化因子受体的细胞。我们还假设，鞘内HIV病毒载量和脑脊液中T细胞的募集可能存在相关性，脑脊液中CTL的存在可能是神经系统疾病的预测因素。

DESCRIPTION (provided by applicant): This proposal responds to PA-01-072, "HIV-1 Infection of the Central Nervous System (CNS)." This study has two major goals. The first goal is to elucidate the mechanisms driving the trafficking of immune effector cells, particularly cytotoxic T-cells (CTL), to the CNS, and the effector functions of these cells that may either palliate or exacerbate neuropathogenesis. The second goal is to determine the relationship between trafficking of antiviral T-cells to cerebrospinal fluid (CSF) and viral load, antiretroviral therapy, and development of neurological disease. In preliminary studies, we determined that multiparameter flow cytometry may be used to detect antigen-specific CD8+ T-cells obtained "ex vivo" from 5-10 ml of CSF. In Specific Aim 1, we will study the frequency and trafficking patterns of HIV-specific CTL in CSF, and determine the relationship of CTL frequency in CSF to systemic and intrathecal immune activation, chemokine expression, HIV viral load and development of CNS disease. In Specific Aim 2, we will assess the effector functions of CSF CTL, including secretion of proinflammatory cytokines (IFN-gamma,, TNF-alpha), cytolytic effector molecules (i.e., perforin, granzymes), and MHC class I restricted lysis of target cells. We will also assess the clonality of HIV-specific CTL in CSF and peripheral blood, and determine the extent of"overlap" between these two populations. Two studies will be performed: first, a cross-sectional study of 25 HIV-infected patients with detectable HIV-specific CTL in perpheral blood; second, a longitudinal study of 40 HIV-infected patients including 10 who are stopping or interrupting highly-active antiretroviral therapy (HAART), 10 who are beginning HAART, 10 clinically stable individuals not on HAART and 10 with symptoms of neurological disease. We hypothesize that systemic lymphocyte activation (including upregulation of LFA-1 and VLA-4) leads to increased extravasation of activated lymphocytes into CSF, and that viral replication within the CNS, followed by a local inflammatory response and secretion of chemokines (i.e., IP-10, MIP-1alpha and MIP-1beta,RANTES) contributes to recruitment of cells expressing receptors for these chemokines in a non antigen-specific manner. We also hypothesize that there may be a correlation between intrathecal HIV viral load and T-cell recruitment to CSF, and that the presence of CTL in CSF may be predictive of neurological disease.