HIV-1 Adaptation in the Central Nervous System

描述（由申请人提供）：HIV在感染后早期侵入中枢神经系统。病毒对中枢神经系统复制的适应性及其免疫后遗症导致高达50%未经治疗的患者出现临床神经病理后遗症。宿主和病毒决定因素都可能介导导致HIV相关痴呆（HIV- d）和轻微运动认知障碍（MMCD）临床综合征的神经病理学。在这项研究中，我们将通过3个特定的目的来研究HIV-1在中枢神经系统中进化的速度和可能的决定因素。SA 1: HIV-1 gp160和nef序列的进化将通过比较原发感染的未治疗患者的血浆和脑脊液病毒进行评估，随访3至5年，采用快速敏感筛选env V1-2 A/4-5长度多态性和克隆序列分析env和nef。同时，将对来自慢性感染患者队列的纵向样本进行血液和脑脊液病毒比较，为期3至5年，以提供相关信息。在发现差异的地方，将进行机器学习算法和多元回归分析，以确定有助于序列进化的单个位置，并注意改变抗体中和的糖基化位点，影响趋向性或假定的神经毒性的V3位置，以及在env和nef中描述的CTL表位。SA 2：在特征明确的尸检样本中，将检查脑脊液、血浆、脑实质区域、脾脏、淋巴结和结肠的前病毒DNA序列和RNA序列，以表征中枢神经系统中HIV群体的组成，并确定有效复制的病毒变体子集。sa3：将在sa1和sa2中鉴定的典型env序列克隆到表达载体中，并评估共受体密度依赖性和使用情况以及抗体中和敏感性。nef和env中假定的HLA限制性CTL表位序列变化将与患者HLA类型相关。总之，这些研究将开始识别和表征艾滋病毒在中枢神经系统进化的免疫决定因素。

DESCRIPTION (provided by applicant): HIV invasion of the central nervous system (CNS) occurs early after infection. Viral adaptation to replication in the CNS and its immunologic sequelae results in clinical neuropathological sequelae in up to 50% of untreated patients. Both host and viral determinants may mediate the neuropathology that results in the clinical syndromes of HIV associated dementia (HIV-D) and minor motor cognitive disorder (MMCD). In this study, we will examine the rate and possible determinants of evolution of HIV-1 in the CNS through 3 specific aims. SA 1: HIV-1 gp160 and nef sequence evolution will be assessed by comparing plasma and CSF virus in untreated patients identified in primary infection that are followed over 3 to 5 years employing rapid and sensitive screening of length polymorphism in V1-2 A/4-5 of env and clonal sequence analysis of env and nef. Concurrently, blood and CSF virus comparisons will be performed on longitudinal samples from a cohort of patients with chronic infection over a 3 to 5 year period to provide. Where differences are found, machine learning algorithms and multiple regression analysis will be performed to identify individual positions that contribute to sequence evolution with attention to glycosylation sites that alter neutralization by antibody, V3 positions that affect tropism or putative neurotoxicity, and CTL epitopes described in both env and nef. SA 2: In well characterized autopsy samples, CSF, plasma, parenchymal brain regions, spleen, lymph node and colon will be examined for proviral DNA sequences and RNA sequences, in order to characterize the composition of the HIV population in CNS and to determine the subset of viral variants that are productively replicating. SA 3: Prototypical env sequences identified in SA 1 and 2 will be cloned into expression vectors and co- receptor density dependence and usage and antibody neutralization susceptibility will be assessed. Sequence change in putative HLA restricted CTL epitopes in nef and env will be correlated with patient HLA type. Together, these studies will begin to identify and characterize immunologic determinants of HIV evolution in the CNS.