Engineering HIV-resistant CAR T cells for a functional HIV cure

项目总结/摘要 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，以及高抗原负荷导致慢性免疫激活，T细胞耗竭， 功能障碍能够完全抑制病毒复制的强效抗逆转录病毒疗法（ART）的出现， 大大降低了艾滋病毒感染的发病率和死亡率。然而，ART必须像HIV一样无限期地服用 在长期稳定的水库中持续存在，因此造成了重大的公共卫生负担， 通过预防性疫苗和更有效的治疗方法来缓解。 考虑到HIV有效地逃避细胞免疫应答，并且潜伏的HIV库优先地被免疫应答的细胞免疫应答。 接种携带相关细胞毒性T淋巴细胞（CTL）逃逸突变的病毒，基因工程 治疗方式可能提供固有免疫的有效替代方案。嵌合抗原受体（CAR）T细胞具有 在临床上消除血细胞癌症方面表现出令人印象深刻的功效，并且CAR T细胞被重新设计为靶向 使用CD 4胞外域（CD 4-CAR T）的HIV代表了一种有效的抗逃逸细胞疗法， 与传统的细胞毒性T淋巴细胞相比具有增强的细胞毒性功能。 我们最近描述了一种显著增强的双共刺激结构域CAR T细胞的产生， 结果显示，该产品（Dual汽车）在体内的表现显著优于第三代CAR T细胞。重要的是这些 研究确定了至少两个额外的障碍，以CD 4-CAR T细胞在体内的功效，这可能会通知翻译， 去诊所首先，CD 4-CAR T细胞快速上调多种抑制性受体，表达转录因子， 与衰竭相关，并在体外显示减弱的功能。其次，我们的研究明确表明， 血浆病毒载量的抑制需要保护CAR T细胞产物免受HIV感染。这项建议 试图通过以下方式解决CD 4-胞外域CAR T细胞疗法中的这些缺陷：1）定义 慢性HIV暴露减弱T细胞功能，2）开发新的组合策略，以充分保护 来自HIV感染的CD 4-CAR T细胞，最终目标是创造一种T细胞免疫疗法， 提高了临床疗效。

Project Summary/Abstract The human immunodeficiency virus (HIV) promptly subverts the host cellular immune response through rapid viral escape, as well as high antigen loads leading to chronic immune activation, T cell exhaustion, and immune dysfunction. The advent of potent antiretroviral therapy (ART) capable of fully suppressing viral replication has drastically reduced the morbidity and mortality of HIV infection. However, ART must be taken indefinitely as HIV persists in long-lived stable reservoirs and thus presents a significant public health burden that can only be alleviated with a preventative vaccine and more potent cure approaches. Given that HIV effectively evades the cellular immune response, and the latent HIV reservoir is preferentially seeded with virus harboring relevant cytotoxic T lymphocyte (CTL)-escape mutations, genetic engineering modalities may offer a potent alternative to intrinsic immunity. Chimeric antigen receptor (CAR) T cells have shown impressive efficacy in eliminating blood cell cancers in the clinic, and CAR T cells re-engineered to target HIV using the CD4 ectodomain (CD4-CAR T) represent a potent escape-resistant cellular therapy demonstrated to have enhanced cytotoxic function over traditional cytotoxic T lymphocytes. We have recently described the creation of a significantly enhanced dual costimulatory domain CAR T cell product (Dual CARs), which significantly outperformed 3rd generation CAR T cells in vivo. Importantly, these studies identified at least two additional hurdles to CD4-CAR T cell efficacy in vivo, which likely informs translation to the clinic. First, CD4-CAR T cells rapidly upregulate multiple inhibitory receptors, express transcription factors associated with exhaustion, and display attenuated function ex vivo. Secondly, our studies definitively show that suppression of plasma viral load requires protection of the CAR T cell product from HIV infection. This proposal seeks to address these deficits in CD4-ectodomain CAR T cell therapy by 1) defining the mechanism(s) by which chronic HIV exposure attenuates T cell function, and 2) developing novel combinatorial strategies to fully protect CD4-CAR T cells from HIV infection, with the ultimate goal of creating a T cell immunotherapy exhibiting enhanced efficacy in the clinic.