Modeling HIV-1 primary transmission in vitro and in vivo

描述(由申请人提供)：HIV-1的传播是一种罕见的事件，它涉及从受感染的捐赠者中从多达1亿种基因型中选择最少的一种创始人基因型。这项研究计划的目标是了解为什么传播是如此选择性，以及什么生物学特性定义了这种罕见的、高度传播的病毒。来自4个C亚型原发感染和1个B亚型感染的方正病毒感染性分子克隆的使用为区分少数高传播性病毒和许多非传播性病毒提供了关键资源。这项研究提案有两个具体目标。第一种是使用Transwell培养方法模拟HIV的体外传播，病毒必须穿过完整的上皮屏障才能到达靶细胞。病毒添加的条件和可用的靶细胞都将改变，以模拟粘膜传播的自然部位和驻留的CD4T细胞靶点。正在测试的假设是，高度可传播的病毒必须既能有效地穿过上皮细胞屏障，又能有效地感染第一个可用的靶细胞，并且这两个特性可以在体外模拟，以区分易传播的病毒和不易传播的病毒。在第二个特定目标中，体外模型的结果将通过创建具有最佳传播的HIV-1包膜的猿猴-人类免疫缺陷病毒包膜嵌合体，并将得到的SIV用于恒河猴的阴道攻击研究来进行测试。在体外和体内研究中，对高传播性和低传播性病毒的基因类型和生物学特性的广泛分析将允许定义定义传播成功的特征。因此，这项研究计划的最终结果将是更好地了解HIV-1传播，以及一个或多个反映创始人病毒而不是晚期分离株的SHIV嵌合病毒，并将为临床前预防研究提供更相关的试剂。

DESCRIPTION (provided by applicant): Transmission of HIV-1 is a rare event that involves extreme, non-random selection of as few as one founder genotype out of as many as 100 million genotypes in the infected donor. The goal of this research proposal is to understand why transmission is so selective, and what biological properties define the rare, highly transmissible virus. The use of infectious molecular clones of founder viruses from 4 subtype C primary infections and 1 subtype B infection provides a key resource to distinguish the few highly transmissible viruses from the many non-transmissible viruses. The research proposal has two specific aims. The first is to model HIV transmission in vitro using transwell cultures where virus must cross an intact epithelial barrier to reach target cells. Both the conditions of virus addition and the available target cells will be varied to mimic the natural sites of mucosal transmission and the resident CD4+ T cell targets. The hypothesis under test is that a highly transmissible virus must be able to both cross the epithelial cell barrier efficiently and infect the first available target cell efficiently, and that these two properties can be modeled in vitro to distinguish readily transmissible viruses from poorly transmissible viruses. In the second specific aim, the results of the in vitro model will be put to the test by creating a simian-human immunodeficiency virus envelope chimera with the best transmitted HIV-1 envelope, and using the resulting SHIV for vaginal challenge studies in rhesus macaques. In both in vitro and in vivo studies, extensive analysis of the genotypic and biological properties of highly transmissible versus poorly transmissible viruses will allow the definition of the characteristics that define transmission success. The end product of this research program will thus be a better understanding of HIV-1 transmission, and one or more SHIV chimeric viruses that reflect founder viruses rather than late-stage isolates, and will provide a much more relevant reagent for preclinical prevention studies.