Persistent STAT5 signaling in polyfunctional CD4 T cells and its application in adoptive T cell therapy

项目概要/摘要 过继性T细胞治疗（ACT）的最新进展，特别是靶向CD 19的嵌合抗原 受体（CAR）T细胞疗法（CD 19 CART），突出了免疫疗法的潜力， 实现持久和治愈性的患者结果。然而，即使是发达国家， CD 19 CART，许多患者对治疗没有反应或死于晚期复发。 此外，到目前为止，ACT通常在治疗大多数实体瘤方面并不有效。主要 有效ACT的障碍包括供体T细胞扩增、持久性和肿瘤- 浸润，以及T细胞效应器功能的丧失-一个称为耗竭的过程。有 对能够克服这些障碍以提高疗效的新策略的需求日益增加 的ACT。具有多功能表型的CD 4 T细胞的存在，其特征在于 伴随产生多种炎性细胞因子，与有利的 临床前模型和癌症患者的治疗结果。但是，如何生成 适用于ACT的多功能CD 4（pfCD 4）T细胞仍然难以捉摸。我们之前报道过， 在抗原刺激期间暴露于白细胞介素7（IL 7）的CD 4 T细胞可以获得 以STAT 5依赖性方式具有多官能性。我们最近的研究表明，异位 在CD 4 T细胞中STAT 5的组成型活性形式（CASTAT 5）的表达诱导基因组- 广泛的转录和表观遗传重塑肿瘤特异性CD 4 T细胞，赋予这些 细胞的多功能性、抗耗竭性和肿瘤浸润能力。重要的是， CASTAT 5可以显著改善CD 19 CAR T细胞的扩增和持久性，从而导致CD 19 CAR T细胞的增殖。 在晚期淋巴瘤小鼠中具有高治愈率。这些新发现构成了我们的基础。 CASTAT 5诱导的表观遗传重塑赋予CD 4 T细胞 多功能性和抗耗竭性，这些特征使CD 4 T细胞具有上级 辅助活性以协调有效的抗肿瘤免疫应答。这种跨学科的多- PI项目将采用我们的特点良好的ACT模型系统，结合尖端的 表观基因组学和单细胞RNA测序技术，以促进我们对 pfCD 4 T细胞的个体发生、异质性、调节电路和作用机制。 具体来说，我们将研究持续的STAT 5信号传导如何诱导和维持pfCD 4 T细胞的表达。 细胞（目标1），CASTAT 5诱导的pfCD 4 T细胞如何增强ACT（目标2），以及 CASTAT 5在人CD 19 CAR T细胞中的效用（Aim 3）。该项目的成功完成将 将CASTAT 5确立为临床适用的策略，以克服阻碍有效治疗的障碍 ACT包括CAR T细胞疗法。

Project summary/abstract Recent advances in adoptive T-cell therapy (ACT), especially CD19-targeting chimeric antigen receptor (CAR) T-cell therapy (CD19CART), have highlighted the potential of immunotherapy to achieve durable and curative patient outcomes. However, even for the well-developed CD19CART, many patients have failed to respond to the treatment or succumbed to late relapse. Moreover, so far ACT in general has not been effective in treating most solid tumors. The major barriers to effective ACT include deficiencies in donor T cell expansion, persistence and tumor- infiltration, as well as loss of T-cell effector function - a process termed exhaustion. There is increasing demand for novel strategies that can overcome these barriers to improve the efficacy of ACT. The presence of CD4 T cells with a polyfunctional phenotype, characterized by concomitant production of multiple inflammatory cytokines, has been associated with favorable therapeutic outcomes in preclinical models and cancer patients. However, how to generate polyfunctional CD4 (pfCD4) T cells suitable for ACT remains elusive. We previously reported that CD4 T cells exposed to interleukin 7 (IL7) during antigenic stimulation can acquire polyfunctionality in a STAT5-dependent manner. Our recent work demonstrated that ectopic expression of a constitutively active form of STAT5 (CASTAT5) in CD4 T cells induces genome- wide transcriptional and epigenetic remodeling in tumor-specific CD4 T cells, endowing these cells polyfunctionality, exhaustion-resistance and tumor-infiltrating capability. Importantly, CASTAT5 can markedly improve the expansion and persistence of CD19CAR T cells, resulting in high cure rate in mice with advanced lymphoma. These new findings form the basis of our central hypothesis that CASTAT5-induced epigenetic remodeling endows CD4 T cells polyfunctionality and exhaustion-resistance, and these features equip CD4 T cells with superior helper activities to orchestrate potent antitumor immune responses. This cross-disciplinary multi- PI project will employ our well-characterized ACT model systems in conjunction with cutting-edge epigenomics and single cell RNA sequencing technologies to advance our understanding of the ontogeny, heterogeneity, regulatory circuitry and mechanism of action of pfCD4 T cells. Specifically, we will investigate how persistent STAT5 signaling induces and maintains pfCD4 T cells (Aim 1), how CASTAT5-induced pfCD4 T cells potentiate ACT (Aim 2), and the potential utility of CASTAT5 in human CD19CAR T cells (Aim 3). Successful completion of this project will establish CASTAT5 as a clinically applicable strategy to overcome the barriers impeding effective ACT including CAR T cell therapy.