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

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 我们的目标是确定HIV-1包膜糖蛋白（Env）的特征，为疫苗接种提供合理的靶点。艾滋病毒-1在很大程度上通过高度多样化阻碍了疫苗接种工作。这种多样化在HIV-1 Env中最为明显，该蛋白负责介导病毒与宿主之间的受体相互作用和融合。由于其位于病毒外部，Env是唯一可以引发体液中和抗体应答的免疫原。虽然已经鉴定出一些广泛中和抗体，但事实证明没有任何策略可以成功指导它们的产生。这可能是由于对感染者体内HIV-1进化轨迹的理解不足，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，HIV-1适应性与病毒进入的速度直接相关。同样，传递性或“传递适合度”将由包膜糖蛋白的特征决定。我们假设HIV-1 Env内的决定簇使病毒更适合，因此有助于病毒的发病机制。此外，我们预测Env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，需要确定这些决定因素，以适当地接种疫苗，以促进体液抗Env反应。一方面，通过防止或限制病毒进化为高度适应性和高致病性变体，预期此类反应的发展具有治疗功效;而“传播适应性”的决定因素的鉴定将为开发预防性疫苗提供靶点。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感染性分子克隆来进行以下工作：使用来自感染个体的纵向病毒分离物鉴定HIV-1适应性的分子决定因素; 2.）通过使用随机化高变序列鉴定Env中最适合的变体; 3.）通过相关的粘膜器官型培养物竞争Env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增效。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. 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.