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，涉及从感染供体的多达1亿个基因型中极端地、非随机地选择少至1个创始基因型。这项研究计划的目标是了解为什么传播具有如此高的选择性，以及这种罕见的高传染性病毒的生物学特性。使用4种C亚型原发性感染和1种B亚型原发性感染的方正病毒的感染性分子克隆，为区分少数高传染性病毒和许多非传染性病毒提供了关键资源。这项研究计划有两个具体目标。第一种方法是利用transwell培养物在体外模拟HIV传播，其中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常驻CD4+ T细胞靶标。所测试的假设是，高传染性病毒必须能够有效地穿过上皮细胞屏障并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，以区分易传染性病毒和低传染性病毒。在第二个具体目标中，将通过创建具有最佳传播HIV-1包膜的猿猴-人类免疫缺陷病毒包膜嵌合体，并将由此产生的SHIV用于恒河猴的阴道攻击研究，对体外模型的结果进行检验。在体外和体内研究中，对高传染性和低传染性病毒的基因型和生物学特性进行广泛分析，将有助于确定确定传播成功的特征。因此，这项研究计划的最终产品将更好地了解HIV-1的传播，以及一种或多种反映创始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.