Evaluation of HIV-1 Env intracytoplasmic domain as an AIDS vaccine immunogen

HIV-1 Env胞质内结构域作为艾滋病疫苗免疫原的评价

• 批准号: 7120828
• 负责人: Ronald C Montelaro
• 金额: $ 21.55万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-05-01 至 2008-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7120828
• 关键词: AIDS vaccines; antibody; antigens; lipids; neutralizing antibody; proteins; role

DESCRIPTION: (provided by applicant): The HIV-1 envelope proteins are recognized as primary immune targets during infection and have been a major focus of AIDS vaccine development to elicit enduring broadly neutralizing antibody responses. These efforts have largely focused on the gp120 and gp41 ectodomains, based on the assumption that the gp41 intracytoplasmic domain (ICD) was not exposed and important for envelope immunogenicity. Recent studies from our lab and others, however, clearly indicate that the ICD is a major determinant of HIV-1 envelope structure, function, and antigenicity and that the ICD can be a potent target for neutralizing antibodies directed to relatively conserved protein segments. We hypothesize that critical segments of the ICD of HIV-1 gp41 are actually located on the exterior of the viral or cellular lipid bilayer and that these segments are important determinants of Env antigenic and immunogenic properties, both by association with other Env domains and as distinct epitopes for neutralizing antibody responses. We hypothesize further that the ICD can be engineered to enhance AIDS vaccine capacity to produce optimal neutralizing antibody responses. We propose in this application to test this hypothesis in 2 specific aims: (i) To determine the topology of ICD sequences in representative clade B and clade C Envs relative to the viral and cellular lipid bilayers, and (ii) To assess the role of the ICD as a determinant of Env antigenicity and immunogenicity with respect to envelope antibody reactivity and neutralization. The structural studies will utilize high resolution membrane protein topology mapping techniques and antibody reactivity assays to define ICD structure in the context of virus-and cell-associated Env and in the context of novel chimeric proteins containing the HIV-1 ICD fused to the ectodomain of influenza virus HA envelope protein. The immunologic studies will employ experimental immunization of rabbits using our established DNA vaccine procedures with codon optimized HIV-1 full length of truncated Envs or engineered HA-gp41 constructs to isolate ICD immunogenicity. It is anticipated that the results of these studies will for the first time define the topology of the HIV-1 ICD and characterize its potential as an immunogen to elicit broadly neutralizing antibodies. The long range goal of this project is to engineer the ICD to optimize the capacity of Env immunogens to elicit enduring broadly reactive neutralizing antibodies. Lay summary: This proposal evaluates the structure of a relatively uncharacterized segment of the HIV-1 envelope and examines the role of these envelope sequences as determinants of viral neutralization properties and for its potential as a vaccine to enhance the production of neutralizing antibodies.

描述：(申请人提供)：HIV-1包膜蛋白在感染过程中被认为是主要的免疫目标，并一直是艾滋病疫苗开发的主要焦点，以诱导持久的广泛中和抗体反应。这些努力主要集中在gp120和gp41胞外结构域，基于gp41胞浆内结构域(ICD)不暴露和对包膜免疫原性重要的假设。然而，我们实验室和其他实验室最近的研究清楚地表明，ICD是HIV-1包膜结构、功能和抗原性的主要决定因素，并且ICD可以成为针对相对保守的蛋白质片段的抗体的有效靶点。我们假设HIV-1gp41的ICD的关键片段实际上位于病毒或细胞脂双层的外部，这些片段是Env抗原性和免疫原性的重要决定因素，既与其他Env结构域相关联，也作为中和抗体反应的不同表位。我们进一步假设，ICD可以被改造成增强艾滋病疫苗的能力，以产生最佳的中和抗体反应。在这一应用中，我们建议在两个特定目标上检验这一假设：(I)确定具有代表性的B分支和C分支包膜蛋白中ICD序列相对于病毒和细胞脂双层的拓扑结构，以及(Ii)评估ICD作为环境抗原性和免疫原性的决定因素在包膜抗体反应性和中和性方面的作用。结构研究将利用高分辨率膜蛋白拓扑图技术和抗体反应性分析来确定病毒和细胞相关环境中的ICD结构，以及包含HIV-1 ICD与流感病毒HA包膜蛋白胞外区融合的新型嵌合蛋白。免疫学研究将使用我们建立的DNA疫苗程序对兔进行实验免疫，使用密码子优化的HIV-1全长截短env或工程HA-gp41构建物来分离ICD的免疫原性。预计这些研究的结果将首次确定HIV-1 ICD的拓扑结构，并表征其作为免疫原诱导广泛中和抗体的潜力。该项目的长期目标是设计ICD，以优化环境免疫原诱导持久的广谱反应性中和抗体的能力。Lay概要：这项建议评估了HIV-1被膜一段相对不具特征的结构，并检查了这些被膜序列作为病毒中和特性的决定因素的作用，以及它作为疫苗促进中和抗体产生的潜力。