VACCINE-TARGETED IDENTIFICATION OF FITNESS DETERMINANTS IN THE HIV-1 ENVELOPE

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 我们的目标是确定HIV-1包膜糖蛋白(Env)的特性，为疫苗接种提供合理的靶点。HIV-1在很大程度上通过高度多样化阻碍了疫苗接种努力。这种多样性在HIV-1环境蛋白中最为明显，这种蛋白负责调节病毒和宿主之间的受体相互作用和融合。由于其位于病毒的外部，Env是唯一能引起体液中和抗体反应的免疫原。虽然已经确定了几种广泛的中和抗体，但还没有一种策略被证明能成功地指导它们的产生。这可能是由于对HIV-1在感染者体内的进化轨迹缺乏了解，以及未能确定病毒传播性的普遍决定因素。在没有药物治疗的情况下，艾滋病毒-1的健康状况与病毒进入的速度直接相关。同样，传播性或“传播适合性”将由包膜糖蛋白的特性决定。我们假设，HIV-1环境中的决定因素使病毒更适合病毒，因此有助于病毒的发病。此外，我们预测在环境中存在促进病毒在人与人之间传播的决定因素。在每种情况下，都需要确定这些决定因素，以便适当地接种疫苗，以促进体液抗环境病毒反应。一方面，这种反应的发展预计会通过防止或限制病毒进化到高适合性和高致病性变种而具有治疗效果；而确定“传播适合性”的决定因素将为开发预防性疫苗提供目标。我们将在双重感染竞争系统中利用含有荧光报告基因的HIV-1感染性分子克隆来做以下工作。)使用来自受感染个体的纵向病毒分离株确定HIV-1适合性的分子决定因素；通过使用随机化的超变量序列确定环境中最合适的变种；通过相关的粘膜器官培养竞争环境变异病毒，以模拟病毒传播并确定成功传播的决定因素。通过这些努力，我们预计能够与我们正在进行的疫苗开发战略协同工作。

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. Our goal is to identify characteristics in the HIV-1 envelope glycoprotein (Env) that would provide rational targets for vaccination. HIV-1 has thwarted vaccination efforts largely through high levels of diversification. This diversification is most apparent in the HIV-1 Env, the protein responsible for mediating receptor interactions and fusion between virus and host. Because of its location on the virus exterior, Env is the only immunogen that can elicit humoral, neutralizing antibody responses. While a few broadly neutralizing antibodies have been identified, no strategy has proved successful in directing their generation. This may be due to a poor understanding of the trajectory of HIV-1 evolution within infected individuals and a failure to identify universal determinants of virus transmissibility. HIV-1 fitness, in the absence of drug treatment, is directly correlated with the rate of virus entry. Likewise, transmissibility or 'transmission fitness' will be determined by characteristics of the envelope glycoprotein. We hypothesize that determinants within HIV-1 Env make the virus more fit and therefore contribute to viral pathogenesis. Moreover, we predict that there exist determinants in Env that promote viral transmission from person to person. In each case, these determinants need to be identified in order to appropriately vaccinate to promote humoral anti-Env responses. On the one hand, the development of such responses would be anticipated to have therapeutic efficacy by preventing or limiting virus evolution to highly fit and highly pathogenic variants; whereas, the identification of determinants of 'transmission fitness' would provide targets for developing prophylactic vaccines. We will utilize HIV-1 infectious molecular clones containing fluorescent reporter genes in a dual-infection competition system to do the following 1.) identify molecular determinants of HIV-1 fitness using longitudinal viral isolates from infected individuals; 2.) identify most fit variants in Env through the use of randomized hypervariable sequences; 3.) compete Env variant viruses through relevant mucosal organotypic cultures to model virus transmission and identify the determinants of successful transmission. Through these efforts we anticipate being able to synergize with our ongoing vaccine development strategies.