Lentivirus Control by CTL and Neutralizing Antibody

描述(由申请人提供)：项目摘要：我的研究职业目标是继续进行由外部资助的慢病毒研究，以解决马和人类医学方面的重要知识空白。虽然我在实现目标方面取得了进展，但作为一名调查员，我实现独立的能力将因此而显著增强。我的大部分时间将用于进行研究，剖析EIAV的适应性免疫控制机制，我计划花费大量时间通过与兽医微生物学和病理学系的高级研究人员合作，获得新的研究技能和知识。该系拥有一批才华横溢的研究人员，在获得校外支持方面有着悠久的历史。主要研究重点是传染病(宿主-寄生虫相互作用)，包括病毒学、寄生虫学、细菌学、疫苗生产和免疫学。拟议研究的总体目标是开发免疫方法，在具有不同MHC I类背景的个体中诱导保护性抗慢病毒CTL反应，并确定中和抗体介导的保护作用以防止慢病毒继续复制的相关性。正在研究的慢病毒系统是马的EIAV。本申请中概述的实验将首先确定编码保守的GAG特异性表位簇的DNA疫苗，加上表达马IL-2/LGG融合蛋白的质粒，然后是牛痘载体Boost，是否会在具有不同MHC I类等位基因的马身上诱导保护性的高亲和力GAG特异性CTL。由于我们的疫苗构建体不会编码包膜蛋白，因此在没有中和抗体的情况下将产生保护作用。另外，我们将识别在进行性EIAV感染过程中出现的病毒包膜变异，并生产能够中和这些变异的马单抗(EMAb)。然后，我们将确定中和抗体介导的保护的要求，通过向SCID马驹注射中和EmAb的组合，在ElAV攻击后10天和14天。这一时间框架与HIV-1暴露后的预防相关，B细胞耗竭研究表明，这是中和抗体参与SIV控制的时间。马SCID缺陷允许针对多种自然发生的慢病毒逃逸变体的中和抗体的保护作用进行测试，而不受内源性B和T细胞反应的影响。这些实验不能在任何其他慢病毒模型系统中完成。 相关性：实现这些目标应该有助于确定CTL和中和抗体对不同人群中自然发生的慢病毒感染的保护作用的相关性。从拟议的研究中获得的信息应该对HIV-1疫苗的设计有影响，因为在那里这种类型的实验是不可能的。

DESCRIPTION (provided by applicant): Project Summary: My research career goals are to continue to conduct extramurally-funded lentiviral research that addresses important knowledge gaps in both equine and human medicine. Although I have made progress towards accomplishing my goals, my ability to achieve independence as an investigator would be significantly enhanced by this award. The majority of my time will be spent conducting research that dissects the mechanisms of adaptive immune control of EIAV, and I plan to spend a significant amount of time acquiring new research skills and knowledge through collaborations with senior investigators in the Department of Veterinary Microbiology and Pathology. The department has an exceptionally talented group of research faculty, with a long history of acquiring extramural support. The major research focus is infectious diseases (host-parasite interactions) including virology, parasitology, bacteriology, vaccine production, and immunology. The overall goals of the proposed research are to develop immunization methods that induce protective antilentiviral CTL responses in individuals with diverse MHC class I backgrounds, and to define the correlates for neutralizing antibody-mediated protection against continued lentivirus replication. The lentiviral system under study is EIAV in horses. The experiments outlined in this application will first determine if a DNA vaccine encoding conserved Gag-specific epitope clusters, augmented with a plasmid expressing an equine IL-2/lgG fusion protein and followed by a vaccinia vector boost, will induce protective high avidity Gag-specific CTL in horses with diverse MHC class I alleles. Because our vaccine constructs will not encode envelope proteins, protective effects will occur in the absence of neutralizing antibody. Separately, we will identify viral envelope variants that arise during progressive EIAV infection, and we will produce equine monoclonal antibodies (EmAb) that neutralize these variants. We will then determine the requirements for neutralizing antibody-mediated protection by infusing combinations of neutralizing EmAbs to SCID foals, 10 and 14 days post-ElAV challenge. This time frame is relevant to post-HIV-1 exposure prophylaxis, and has been shown in B cell depletion studies to be the time when neutralizing antibodies are involved in SIV control. The equine SCID defect allows the protective effects of neutralizing antibodies directed against multiple naturally-occurring lentivirus escape variants to be tested without the influence of endogenous B and T cell responses. These are experiments that cannot be done in any other lentivirus model system. Relevance: Accomplishing these aims should help define the correlates for CTL- and neutralizing antibody-mediated protection against a naturally-occurring lentivirus infection in a diverse population. The information obtained from the proposed studies should have implications for HIV-1 vaccine design, where experiments of this type are not possible.