Brain HIV-1 isolates/envelopes: CD4 dependence, fusogenicity and neurotoxicity

大脑 HIV-1 分离物/包膜：CD4 依赖性、融合性和神经毒性

• 批准号: 8133882
• 负责人: Julio Martin-Garcia
• 金额: $ 44.75万
• 依托单位: DREXEL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2014-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8133882
• 关键词: AIDS neuropathy; Acquired Immunodeficiency Syndrome; Affinity; Antibodies; Avidity; Biological Assay; Brain; CCR5 gene; CD4 Antigens; CXCR4 gene; Cell Line; Cells; Central Nervous System Infections; Clinical; Cloning; Complement; Data; Dependence; Disease; Encephalitis; Epidemic; Evolution; Genes; Genetic; Genetic Recombination; Genome; Glycoproteins; Goals; HIV; HIV Envelope Protein gp120; HIV-1; Health; Impairment; In Vitro; Individual; Infection; Lead; Light; Measures; Membrane Glycoproteins; Microglia; Molecular Conformation; Nerve Degeneration; Neuraxis; Neurocognitive; Neurologic; Neurotropism; Patients; Peptides; Peripheral; Phenotype; Polymerase Chain Reaction; Rattus; Receptor Cell; Relative (related person); Reporting; Research; Research Personnel; Role; Sampling; Sequence Analysis; Spleen; System; Systemic infection; Testing; Tissues; Tropism; Variant; Viral; Virus; Virus Diseases; brain tissue; cell type; env Gene Products; env Genes; env Glycoproteins; in vivo; inhibitor/antagonist; macrophage; mutant; neuroprotection; neurotoxicity; neurovirulence; novel; receptor; small molecule

DESCRIPTION (provided by applicant): The HIV-1/AIDS epidemic continues to spread at an alarming rate world-wide, despite considerable efforts to control it. Central nervous system (CNS) infection by HIV-1 is common and occurs early after systemic infection. Sequence analysis has indicated that the virus may evolve independently in the CNS, probably resulting in adaptation to replication in microglia and macrophages within the brain. However, the potential mechanisms and phenotypic consequences of such adaptation are not well understood. HIV-1 enters cells through the sequential interactions of the viral envelope surface glycoprotein subunit gp120 with the main host cell receptor CD4, and a co-receptor (mainly CCR5 and/or CXCR4). It was previously reported that a primary, peripheral HIV-1 isolate adapted in vitro to replicate in microglial cells acquired increased fusion capacity concurrently with lower CD4 dependence and altered envelope conformation and sensitivity to antibodies and entry inhibitors. Due to the low levels of CD4 in microglial cells and macrophages, and the relative immunological isolation of the CNS, it is hypothesized that viruses containing envelope glycoproteins with similar phenotypes (low CD4 dependence, high fusogenicity and altered sensitivity to entry inhibitors) will arise in vivo as a consequence of viral adaptation to replication in microglial cells and brain macrophages. Preliminary studies have shown that envelope genes amplified from brain tissue feature the above phenotype (including significantly increased sensitivity to a novel allosteric inhibitor of gp120, HNG-105), while those from peripheral tissues do not. However, it is not clear whether viral isolates recovered from brain tissue have this phenotype, as well as the potential role of these phenotypic features in neurotoxicity and neurovirulence. Therefore, the goals of this application are: (i) to determine the phenotypes (CD4 dependence, fusogenicity, cell tropism) of viral isolates recovered from brain and spleen, and of authentic envelopes generated by single genome amplification, from HIV patients with various degrees of neurocognitive impairment; (ii) to define the relationship between these phenotypes and altered sensitivity to two selected, prototypic entry inhibitors (BMS- 378806 and HNG-105) and to identify viral determinants for the phenotypic differences; and (iii) to determine neurotoxicity of viral isolates and envelopes and to define the potential role of these entry inhibitors in decreasing neurotoxicity. Altogether, these studies will provide a functional analysis of the in vivo evolution of HIV-1 in the CNS, complementing previous genetic studies, and will help define a critical correlation between low CD4 dependence, fusogenicity and macrophage tropism, with in vitro neurotoxicity and neurovirulence in vivo, and with an altered sensitivity to specific entry inhibitors, which will potentially allow more targeted approaches for the particular inhibition of replication o viruses present in the CNS of HIV-1-infected patients. PUBLIC HEALTH RELEVANCE: ese studies will extend our understanding of the mechanisms involved in the neurotropism and neurovirulence of HIV-1. They can also potentially lead to more appropriate approaches for the specific inhibition of infection by viruses that replicate in the brain of HIV-1-infected patients and, subsequently, result in a reduction of HIV-1-associated neurological complications.

描述（由申请人提供）：尽管为控制它而做出了巨大努力，但HIV-1/AIDS流行仍以惊人的速度以惊人的速度传播。 HIV-1感染中枢神经系统（CNS）是常见的，并且发生在全身感染后的早期。序列分析表明，该病毒可能在中枢神经系统中独立发展，可能导致对大脑内部小胶质细胞和巨噬细胞复制的适应。然而，这种适应的潜在机制和表型后果尚不清楚。 HIV-1通过病毒包膜表面糖蛋白亚基GP120与主宿主细胞受体CD4和共受体（主要是CCR5和/或CXCR4）的顺序相互作用进入细胞。先前据报道，在获得的小胶质细胞中复制的主要外周HIV-1分离物在获得的小胶质细胞中复制增加了与CD4依赖性较低的融合能力，并改变了CD4的依赖性，并改变了包络构象和对抗体和入口抑制剂的敏感性。由于小胶质细胞和巨噬细胞中的CD4水平较低以及CNS的相对免疫学分离，因此假设含有具有相似表型的包膜糖蛋白的病毒（CD4依赖性低，较高的融合性和对进入抑制剂的敏感性）将在vivo中的敏感性变化），这将是对现实的敏感性的改变）巨噬细胞。初步研究表明，从脑组织扩增的包膜基因具有上述表型（包括对新型GP120，HNG-105的新型变构抑制剂的敏感性显着提高，而外周组织的敏感性则没有。但是，尚不清楚从脑组织中回收的病毒分离株是否具有这种表型，以及这些表型特征在神经毒性和神经动力毒害中的潜在作用。因此，该应用的目标是：（i）确定从大脑和脾脏中回收的病毒分离株的表型（CD4依赖性，融合性，细胞托作），以及由单个基因组扩增产生的真实信封，来自各种神经认知障碍的HIV患者产生的真实信封； （ii）定义这些表型与对两个选定的原型进入抑制剂（BMS-378806和HNG-105）的敏感性改变的关系，并确定表型差异的病毒决定因素； （iii）确定病毒分离株和信封的神经毒性，并确定这些进入抑制剂在降低神经毒性中的潜在作用。总体而言，这些研究将提供有关CNS中HIV-1体内进化的功能分析，对先前的遗传研究进行补充，并有助于定义低CD4依赖性，融合型和巨噬细胞狂热性的临界相关性，并与更具变性的临界率允许对进入剂量的临界率，从而允许使用特定的临界效率。 HIV-1感染患者中枢神经系统中存在的复制O病毒的特殊抑制作用。公共卫生相关性：ESE研究将扩展我们对HIV-1神经性和神经动力学涉及的机制的理解。它们还可能导致更合适的方法，以通过在HIV-1感染患者的大脑中复制的病毒对感染的特定抑制作用，并随后导致HIV-1相关神经系统并发症的降低。