Overcoming the hurdles to successful CAR T cell therapy for a functional HIV cure

项目总结/摘要 该提案寻求必要的资金，以促进丹尼尔克莱本博士的职业过渡到一个 独立的学术科学家该提案提出的最初目标是建立在基本的艾滋病毒 候选人的病毒学，免疫学和病原体-宿主相互作用的专业知识，并利用这些技能 致力于在小动物模型中的转化努力，旨在实现功能性HIV治愈。此外，委员会认为， 职业发展计划概述了获得执行以下任务所需的宝贵技能的途径： 这一建议以及向独立过渡。最后，从成功的 这些实验的执行将产生申请R 01级资助的初步数据。 人类免疫缺陷病毒（HIV）通过快速的免疫应答迅速破坏宿主的细胞免疫应答。 病毒逃逸和高抗原负荷导致慢性免疫激活和T细胞功能障碍。组合 抗逆转录病毒疗法（ART）已经大大降低了艾滋病毒感染的发病率和死亡率，但必须 无限期地服用，因为艾滋病毒在长期稳定的储存库中持续存在，因此对公共卫生构成重大威胁。 负担一种清除病毒库的方法，称为“休克和杀死”，依赖于潜伏期逆转剂 （LRA）重新激活潜伏感染的细胞，使它们可以被免疫系统清除。然而，在这方面， 测试LRA的临床试验几乎没有取得成功，这可能是由于天然细胞的功能障碍， 免疫反应基因工程方式可能提供一个有吸引力的替代固有免疫力。 嵌合抗原受体（CAR）T细胞使用CD 4胞外域（CD 4-CAR）重新工程化以靶向HIV 代表了一种抗逃逸的“杀死”机制，其被证明具有增强的细胞毒性功能。因此，我们认为， 我们假设CD 4-CAR T细胞将是一种有希望的能够抑制HIV的干预措施， 复制并有效地靶向病毒库。 为了快速测试和优化我们的方法，我们利用了BLT人源化HIV感染小鼠模型。 我们的初步结果表明，CD 4-CAR T细胞对抗原有强烈的反应，扩增高达1000倍， 在体内，并显着保护HIV感染的BLT小鼠的快速CD 4 + T细胞的损失。此外，我们改进了 CD 4-CAR T细胞的扩增潜力和细胞毒性功能，并能够保护CD 4-CAR T细胞 艾滋病毒感染。然而，尽管它们能够通过ART增强病毒抑制，但CAR T细胞疗法 单独不能持久抑制BLT小鼠的病毒血症。我们建议从以下方面解决这一不足 具体目标：1）确定病毒复制能力对CAR T细胞功效的影响，2）绘制个体发育图， 体内耗尽的CAR T细胞，以及3）询问先天免疫系统在调节CAR T细胞中的作用 细胞功能这些目标的实现将加深我们对T细胞免疫调节因子的理解。 研究人员正在研究慢性病毒感染的功能障碍，希望将这些发现转化为功能性HIV治疗。

Project Summary/Abstract This proposal seeks the necessary funding to facilitate the career transition of Dr. Daniel Claiborne to an independent academic scientist. The original aims brought forth in this proposal build upon the basic HIV virology, immunology, and pathogen-host interaction expertise of the candidate and leverage these skills towards translational efforts in a small animal model aimed at achieving a functional HIV cure. Furthermore, the career development plan outlines a path towards acquiring valuable skills necessary for the execution of this proposal as well as the transition to independence. Finally, the data generated from the successful execution of these experiments will yield the preliminary data to apply for R01-level funding. The human immunodeficiency virus (HIV) promptly subverts the host cellular immune response through rapid viral escape and high antigen loads leading to chronic immune activation and T cell dysfunction. Combination antiretroviral therapy (ART) has drastically reduced the morbidity and mortality of HIV infection, but must be taken indefinitely as HIV persists in long-lived stable reservoirs and thus presents a significant public health burden. One approach to purging the viral reservoir, termed “shock and kill”, relies on latency reversing agents (LRAs) to reactivate latently infected cells such that they can be cleared by the immune system. However, clinical trials testing LRAs have achieved little success, perhaps due to the dysfunction of the natural cellular immune response. Genetic engineering modalities may offer an attractive alternative to intrinsic immunity. Chimeric antigen receptor (CAR) T cells re-engineered to target HIV using the CD4 ectodomain (CD4-CAR) represent an escape-resistant “kill” mechanism demonstrated to have enhanced cytotoxic function. Therefore, we hypothesized that CD4-CAR T cells would be a promising intervention capable of suppressing HIV replication and effectively targeting the viral reservoir. To rapidly test and optimize our approach, we made use of the BLT humanized mouse model of HIV infection. Our preliminary results demonstrate that CD4-CAR T cells respond robustly to antigen, expand up to 1000-fold in vivo, and significantly protect HIV-infected BLT mice from rapid CD4+ T cell loss. Furthermore, we improved the expansion potential and cytotoxic function of CD4-CAR T cells, and were able to protect CD4-CAR T cells from HIV infection. However, despite their ability to enhance viral suppression with ART, CAR T cell therapy alone was unable to durably suppress viremia in BLT mice. We propose to address this deficit in the following specific aims: 1) Determine the effect of viral replication capacity on CAR T cell efficacy, 2) map the ontogeny of exhausted CAR T cells in vivo, and 3) interrogate the role of the innate immune system in modulating CAR T cell function. Completion of these aims will enhance our understanding of the factors contributing to T cell dysfunction in chronic viral infections, with the hope of translating these findings towards a functional HIV cure.