HIV-1 Env conformation and tropism in brain colonization and neuroAIDS

HIV-1 Env 构象和向性在大脑定植和神经艾滋病中的作用

• 批准号: 9203076
• 负责人: PAUL R CLAPHAM
• 金额: $ 41.88万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-01 至 2019-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9203076
• 关键词: AIDS Dementia Complex; Acquired Immunodeficiency Syndrome; Affect; Affinity; Binding; Biological Assay; Brain; DNA; Data; Dementia; Detection; Development; Disease; Evolution; HIV; HIV Envelope Protein gp120; HIV-1; Immune; Improve Access; Infection; Investigation; Knowledge; Measures; Mediating; Messenger RNA; Minor; Molecular Conformation; Neurocognitive; Neurologic; Neurons; Neurotropism; Patients; Population; Property; Proviruses; Risk; Staging; Structure; T-Lymphocyte; Time; Tissues; Tropism; V3 Loop; Variant; Virus; Virus Replication; brain tissue; design; insight; macrophage; nervous system disorder; neuroAIDS; neurotoxicity; neurotropic; neurovirulence; receptor

Highly mac-tropic HIV-1 R5 Envs that efficiently bind CD4 are associated with HIV neurological disease including HIV associated dementia (HAD). However, our knowledge of the properties and determinants of Envs that colonize brain and evolve into highly mac-tropic, neurovirulent variants are incomplete. Without this, we will not fully understand how and where neurotropic HIV-1 strains arise and develop into neurovirulent forms. Our preliminary data shows that R5 Envs derived from brain tissue of subjects without or with only minor neurocognitive disease (N/MCs) were mainly non-mac-tropic compared to those in HAD brain. This data suggests that mac-tropism is not required for HIV to enter brain tissue and opens up the possibility that HIV is carried in by infected T-cells, before mac-tropic and neurovirulent variants evolve. Env determinants that confer mac-tropism in HAD include residues within or proximal to the CD4bs. However, a single universal Env determinant of mac-tropism has not been identified and residues in different parts of gp120 e.g. the V1V2 and V3 loops were shown to modulate mac-tropism. These residues presumably increase the affinity of the Env trimer for CD4 either (1) directly via changes in contact residues or (2) indirectly by improving access to CD4 or enhancing CD4-induced conformational changes. We recently established a trimeric Env: CD4 binding assay, which shows mac-tropic Env trimers from brain bind CD4 efficiently, while non-mac-tropic Envs don't. We will use this and other assays to investigate how Env conformation and function varies in immune and brain tissue of N/MC and HAD subjects. Our hypothesis is that HAD is determined by the evolution of Envs with a higher affinity for CD4, that (1) carry less tightly closed Env trimers with a more exposed CD4bs, (2) are more easily triggered by CD4 and (3) mediate efficient macrophage infection. We propose 3 aims: Aim 1: To analyze HIV-1 replication and tropism in immune and brain tissue of N/MC subjects. We will establish whether envs recovered from brain of N/MC subjects are derived from actively replicating virus and the extent they are mac-tropic. Aim 2: To establish how Env conformation, tropism, receptor interactions and neurotoxicity vary in N/MC and HAD subjects. We will investigate how Env trimer conformation and function vary between immune and brain tissue of N/MC and HAD subjects. Aim 3: To identify determinants in gp120 and gp41 that modulate mac-tropism and evaluate their impact on Env conformation and function. We will identify Env determinants and properties associated with (1) colonization and viral replication in brain tissue and (2) neurovirulence and neuroAIDS. We will provide new insights to help develop strategies to identify HIV+ subjects at risk of neuroAIDS and `cure' approaches to attack persistent HIV in the CNS.

有效结合 CD4 的高度亲和性 HIV-1 R5 Env 与 HIV 神经系统疾病相关 包括艾滋病毒相关性痴呆（HAD）。然而，我们对环境的属性和决定因素的了解 定植于大脑并进化成高度宏观性、神经毒性的变异体是不完整的。没有这个，我们 无法完全理解嗜神经性 HIV-1 病毒株是如何以及在何处产生并发展成神经毒力形式的。 我们的初步数据表明，R5 Envs 源自受试者的脑组织，没有或只有 与 HAD 大脑中的疾病相比，轻微神经认知疾病 (N/MC) 主要是非mac-tropic 性的。 该数据表明，HIV 不需要向脑组织进入脑组织，因此开启了可能性 HIV是由受感染的T细胞携带的，然后才进化出亲宏性和神经毒性的变异体。环境决定因素 在HAD中赋予宏向性的残基包括CD4b内或邻近CD4b的残基。然而，单一通用 宏向性的 Env 决定因素尚未确定，并且 gp120 的不同部分中存在残基，例如V1V2 和 V3 环被证明可以调节宏向性。这些残基可能增加了亲和力 CD4 的环境三聚体（1）直接通过接触残基的变化或（2）间接通过改善接触 CD4 或增强 CD4 诱导的构象变化。我们最近建立了三聚体 Env: CD4 结合 分析表明，来自大脑的 mac 亲性 Env 三聚体能有效结合 CD4，而非 mac 亲性 Env 则不能。 我们将使用这个和其他测定来研究 Env 构象和功能在免疫和免疫系统中如何变化。 N/MC 和 HAD 受试者的脑组织。我们的假设是 HAD 是由 Envs 的进化决定的 对 CD4 具有更高的亲和力，(1) 携带不太紧密闭合的 Env 三聚体和更多暴露的 CD4b，(2) 更容易被 CD4 触发，并且 (3) 介导有效的巨噬细胞感染。我们提出3个目标： 目标 1：分析 N/MC 受试者免疫和脑组织中的 HIV-1 复制和趋向性。我们将 确定从 N/MC 受试者大脑中恢复的环境是否源自活跃复制的病毒，以及 它们的宏向性程度。 目标 2：确定 N/MC 和 N/MC 中 Env 构象、向性、受体相互作用和神经毒性如何变化 有科目。我们将研究免疫和大脑之间的 Env 三聚体构象和功能如何变化 N/MC 和 HAD 受试者的组织。 目标 3：确定 gp120 和 gp41 中调节 mac 向性的决定因素并评估其对 Env 构象和功能。我们将确定与 (1) 相关的环境决定因素和属性 脑组织中的定植和病毒复制以及（2）神经毒力和神经艾滋病。我们将提供新的 帮助制定策略来识别有神经艾滋病风险的 HIV+ 受试者和“治愈”方法 攻击中枢神经系统中持续存在的艾滋病毒。