MOLECULAR ANALYSIS & MODELING OF HIV-1 TRANSMISSION, CONTAINMENT AND ESCAPE

分子分析

• 批准号: 8172395
• 负责人: Eric Hunter
• 金额: $ 5.48万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-01 至 2011-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8172395
• 关键词: Address; Antibodies; Autologous; Binding; Biological; CCR5 gene; CD4 Positive T Lymphocytes; Clinical; Computer Retrieval of Information on Scientific Projects Database; Containment; Cytotoxic T-Lymphocytes; Epitopes; Exhibits; Funding; Gagging; Genes; Genome; Genomic Imprinting; Genomics; Grant; HIV-1; Human; Immunity; Infection; Institution; Learning; Left; Length; Location; Modeling; Molecular Analysis; Molecular Cloning; Monoclonal Antibodies; Mutation; Pathogenesis; Plasma; Property; RNA; Research; Research Personnel; Resistance; Resources; Source; Surface; T cell response; Testing; United States National Institutes of Health; Vaccine Research; Viral; Virion; Virus; genome-wide; global health; glycosylation; macrophage; microbicide; monocyte; pressure; response; transmission process

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This study addresses Grand Challenge #6 of the Global Health Initiative: Learn which immunological responses provide protective immunity (against HIV-1). Identification of full-length transmitted HIV-1 genomes could be instrumental in HIV-1 pathogenesis, microbicide, and vaccine research by enabling direct analysis of those viruses actually responsible for productive clinical infection. We have shown in 12 acutely infected subjects (9 clade B and 3 clade C) that complete HIV-1 genomes of transmitted/founder viruses can be inferred by single genome amplification and sequencing of plasma virion RNA. This allowed for molecular cloning and biological analysis of transmitted/founder viruses and comprehensive genome-wide assessment of the genetic imprint left on the evolving virus quasispecies by a composite of host selection pressures. Transmitted viruses encoded intact canonical genes (gag-pol-vif-vpr-tat-rev-vpu-env-nef) and replicated efficiently in primary human CD4(+) T lymphocytes but much less so in monocyte-derived macrophages. Transmitted viruses were CD4 and CCR5 tropic and demonstrated concealment of coreceptor binding surfaces of the envelope bridging sheet and variable loop 3. At 2 mo after infection, transmitted/founder viruses in three subjects were nearly completely replaced by viruses differing at two to five highly selected genomic loci; by 12-20 mo, viruses exhibited concentrated mutations at 17-34 discrete locations. These findings reveal viral properties associated with mucosal HIV-1 transmission and a limited set of rapidly evolving adaptive mutations driven primarily, but not exclusively, by early cytotoxic T cell responses. We have recently described two autologous monoclonal antibodies, 6.4C and 13.6A, generated from a Zambian subject, that each recognize a V1V2-dependent target on the founder Env. Using these Mabs, we identified two mutations in the V1V2 domain that were involved in escape at the single antibody level. We have extended these studies to test whether a change in glycosylation is necessary for Nab resistance and to further define epitopes of the Mabs.

该子项目是利用该技术的众多研究子项目之一 资源由 NIH/NCRR 资助的中心拨款提供。子项目及 研究者 (PI) 可能已从 NIH 的另一个来源获得主要资金， 因此可以在其他 CRISP 条目中表示。列出的机构是 对于中心来说，它不一定是研究者的机构。 这项研究解决了全球健康倡议的重大挑战 #6：了解哪些免疫反应可提供保护性免疫力（针对 HIV-1）。全长传播的 HIV-1 基因组的鉴定可以通过直接分析那些实际导致有效临床感染的病毒，从而有助于 HIV-1 发病机制、杀微生物剂和疫苗研究。我们在 12 名急性感染受试者（9 个 B 分支和 3 个 C 分支）中证明，可以通过单基因组扩增和血浆病毒体 RNA 测序来推断传播/创始病毒的完整 HIV-1 基因组。这使得可以对传播/创始病毒进行分子克隆和生物学分析，并对宿主选择压力的综合作用在进化的病毒准种上留下的遗传印记进行全面的全基因组评估。 传播的病毒编码完整的规范基因（gag-pol-vif-vpr-tat-rev-vpu-env-nef），并在原代人CD4（+）T淋巴细胞中有效复制，但在单核细胞衍生的巨噬细胞中复制效率低得多。传播的病毒是 CD4 和 CCR5 向性的，并且表现出包膜桥接片和可变环 3 的辅助受体结合表面的隐藏。感染后 2 个月，三名受试者中的传播/创始人病毒几乎完全被 2 至 5 个高度选择的不同病毒所取代基因组位点；到 12-20 个月时，病毒在 17-34 个离散位置表现出集中突变。 这些发现揭示了与粘膜 HIV-1 传播相关的病毒特性，以及主要但不完全由早期细胞毒性 T 细胞反应驱动的一组有限的快速进化的适应性突变。 我们最近描述了从赞比亚受试者产生的两种自体单克隆抗体 6.4C 和 13.6A，每种抗体都能识别创始人 Env 上的 V1V2 依赖性靶标。使用这些单克隆抗体，我们在单抗体水平上鉴定了 V1V2 结构域中与逃逸有关的两个突变。我们扩展了这些研究，以测试糖基化的变化是否是 Nab 抗性所必需的，并进一步定义 Mab 的表位。