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

项目摘要/摘要 过继T细胞治疗，尤其是CD19靶向嵌合抗原治疗的研究进展 受体(CAR)T细胞疗法(CD19CART)，突显了免疫疗法在 实现持久和治愈的患者结果。然而，即使对于发达的 CD19CART，许多患者对治疗无效或死于晚期复发。 此外，到目前为止，ACT总体上并不能有效地治疗大多数实体瘤。少校 有效ACT的障碍包括供者T细胞扩增、持久性和肿瘤- 渗透，以及T细胞效应器功能的丧失--这一过程称为耗竭。的确有 对能够克服这些障碍以提高疗效的新战略的需求不断增加 ACT的。具有多功能表型的CD4T细胞的存在，特征是 伴随产生的多种炎性细胞因子，一直与有利的 临床前模型和癌症患者的治疗结果。但是，如何生成 适合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， 抗原刺激过程中暴露于白介素7(IL7)的CD4T细胞可获得 以依赖于STAT5的方式实现多功能性。我们最近的研究证明了这种不同寻常的 组成活性形式的STAT5(CASTAT5)在CD4T细胞中的表达诱导基因组- 肿瘤特异性CD4T细胞的广泛转录和表观遗传重塑，赋予这些 细胞的多功能性、抗力竭和肿瘤侵袭能力。重要的是 CASTAT5可显著提高CD19CAR T细胞的扩增和持久性，从而 在晚期淋巴瘤小鼠中的治愈率很高。这些新的发现构成了我们的 中心假设CASTAT5诱导的表观遗传重塑赋予CD4T细胞 多功能和抗疲劳，这些功能为CD4T细胞配备了优越的 辅助活动，以协调有效的抗肿瘤免疫反应。这项跨学科、多学科的 PI项目将使用我们特点良好的ACT模型系统和尖端技术 表观基因组学和单细胞RNA测序技术 PfCD4T细胞的个体发育、异质性、调节回路和作用机制。 具体地说，我们将研究持续的STAT5信号如何诱导和维持pfCD4T 细胞(目标1)，CASTAT5诱导的pfCD4T细胞如何增强ACT(目标2)，以及 CASTAT5在人CD19CAR T细胞中的应用(目标3)这个项目的成功完成将 将CASTAT5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细胞治疗。

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.