Molecular regulation of HIV-1 assembly, release and cell-to-cell transmission

HIV-1组装、释放和细胞间传播的分子调控

基本信息

批准号：
8440811
负责人：
Markus Thali
金额：
$ 34.66万
依托单位：
UNIVERSITY OF VERMONT & ST AGRIC COLLEGE
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-04-22 至 2014-06-30
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): Successful dissemination of HIV-1 in infected individuals depends on efficient transmission of viral particles from infected (producer) to uninfected (target) cells. In vitro propagation studies have established that HIV-1 particles are most effectively transmitted to target cells if they bud into the cleft of the so-called virological synapse (VS) that forms between producer and target cells. The events leading to the formation, maintenance and disassembly of this synapse are poorly understood. Previously, we and other laboratories have established that HIV-1 particles exit from cells at sites that are enriched in tetraspanins. These cellular membrane proteins normally function as organizers of plasma membrane-based processes, including cell-cell fusion and adhesion. Our preliminary data suggest that individual members of the tetraspanin family are not required for virus release, but they point to a role of these proteins in regulating virus transfer to target cells. We thus propose to evaluate if tetraspanins in producer cells are regulatory cofactors necessary for efficient cell-to-cell transmission of HIV-1 particles. We will also analyze the effects of virus-mediated downregulation of tetraspanins. Altogether, these studies will provide further insight into the molecular mechanisms underlying HIV-1 spread and thus pathogenesis. In the Specific Aims of this proposal we propose: 1) To test the hypothesis that tetraspanins inhibit HIV-1-induced membrane fusion, thus allowing cell-to-cell transfer without fusion of producer and target cell. 2) To determine if tetraspanins in HIV-1 producer cells promote efficient transmission of viral particles to target cells by supporting the formation, the organization and the disassembly of the VS. 3) To examine the kinetics, determinants and potential consequences of HIV-1-induced tetraspanin downregulation in infected cells.

描述（由申请人提供）：HIV-1 在受感染个体中的成功传播取决于病毒颗粒从受感染（生产者）细胞到未受感染（目标）细胞的有效传播。体外传播研究已经证实，如果 HIV-1 颗粒萌芽到生产细胞和靶细胞之间形成的所谓病毒突触 (VS) 的缝隙中，它们就能最有效地传播到靶细胞。人们对导致该突触的形成、维持和分解的事件知之甚少。此前，我们和其他实验室已经确定，HIV-1 颗粒从富含四跨膜蛋白的位点的细胞中排出。这些细胞膜蛋白通常充当基于质膜的过程的组织者，包括细胞与细胞的融合和粘附。我们的初步数据表明，四跨膜蛋白家族的各个成员并不是病毒释放所必需的，但它们指出了这些蛋白质在调节病毒转移到靶细胞中的作用。因此，我们建议评估生产细胞中的四跨膜蛋白是否是 HIV-1 颗粒有效细胞间传播所必需的调节辅因子。我们还将分析病毒介导的四跨膜蛋白下调的影响。总而言之，这些研究将进一步深入了解 HIV-1 传播的分子机制以及发病机制。在该提案的具体目标中，我们提出： 1) 检验四跨膜蛋白抑制 HIV-1 诱导的膜融合的假设，从而允许细胞间转移而不产生生产细胞和靶细胞的融合。 2) 确定HIV-1生产细胞中的四跨膜蛋白是否通过支持VS的形成、组织和分解来促进病毒颗粒向靶细胞的有效传播。 3) 检查感染细胞中 HIV-1 诱导的四跨膜蛋白下调的动力学、决定因素和潜在后果。