Transcriptional Control of T Cell Function

项目总结 T细胞对癌症的反应表现为低反应性，其特征是高水平的抑制性。 受体表达，低细胞因子产生，以及未能控制肿瘤生长。我们之前已经确定 小鼠和人T细胞共有的持续抗原刺激诱导的转录程序 应对慢性病毒感染和肿瘤。我们将这一程序与核受体的激活联系起来 4亚家族A组(NR4A)转录因子(TF)，在慢性刺激过程中被有效诱导。 我们还确定了NR4A敏感的调节元件，这些元件可在响应慢性疾病的T细胞中获得 病毒感染和肿瘤。我们发现，NR4A转录因子同时促进抑制性受体的表达和 有限的细胞因子产生，导致T细胞耗尽状态，减少嵌合抗原受体 表达T(CAR-T)细胞抗实体瘤活性。CAR-T细胞被设计为缺乏所有三种NR4A转录因子 分化为一个独特的群体，与野生型T细胞相比具有强大的抗肿瘤活性。我们相通了 NR4A缺乏症患者碱性亮氨酸拉链(BZIP)转录因子表达和活性的增加 T细胞数量高于野生型。在新的初步研究中，我们发现部分缺失NR4A转录因子的CAR-T细胞 也提供了比野生型CAR-T细胞更好的保护，但具有独特的抗疲劳表型 这些细胞可以发挥效应器功能，并具有更高的长期存活潜力。在此应用程序中，我们 将检验这样的假设，即NR4A和bZIP转录因子可以被“调整”来控制转录程序和 “力竭抵抗”CAR-T细胞在肿瘤中的作用在目标1中，我们将确定治疗的影响 使用抗体或小分子干预“抗力竭”CAR-T的功能和存活 细胞。在目标2中，我们将确定NR4A调节的bZIP转录因子对NR4A缺陷的功能的贡献 CAR-T细胞及其对“抗疲劳”CAR-T细胞转录程序的影响。在《目标3》中，我们将 确定NR4A转录因子对调节元件上bZIP-TF活性的影响，并确定染色质相关的联合 这些因素可能是控制“抗疲劳”CAR-T细胞功能的靶点。预期的结果 我们建议的研究之一是全面了解NR4A和bZIP转移因子对CAR-T细胞的影响 在肿瘤中，我们将通过它来确定实用的策略来“调整”CAR-T细胞的功能以用于治疗 通过控制转录程序获益。

PROJECT SUMMARY T cells responding to cancer develop a hyporesponsive phenotype, characterized by high levels of inhibitory receptor expression, low cytokine production, and a failure to control tumor growth. We have previously identified a transcriptional program induced by persistent antigen stimulation that was shared by mouse and human T cells responding to chronic viral infections and tumors. We linked this program to activation of the Nuclear Receptor Subfamily 4 Group A (NR4A) transcription factors (TFs), which are potently induced during chronic stimulation. We also identified NR4A-sensitive regulatory elements that became accessible in T cells responding to chronic viral infection and tumors. We found that NR4A TFs concomitantly promoted inhibitory receptor expression and limited cytokine production, leading to an exhausted T cell state that reduced chimeric antigen receptor expressing T (CAR-T) cell activity against solid tumors. CAR-T cells engineered to lack all three NR4A TFs differentiated to a unique population with potent anti-tumor activity compared to wild-type T cells. We connected this improved function to increased expression and activity of basic leucine zipper (bZIP) TFs in NR4A-deficient T cells than in wild-type. In new preliminary studies, we found that CAR-T cells with a partial loss of NR4A TFs also provided better protection than wild-type CAR-T cells, but had a unique “exhaustion resistant” phenotype that are poised for effector function and have increased potential for long term survival. In this application, we will test the hypothesis that NR4A and bZIP TFs can be “tuned” to control the transcriptional programs and function of “exhaustion resistant” CAR-T cells in tumors. In Aim 1, we will determine the impact of therapeutic interventions, using antibodies or small molecules, on the function and survival of “exhaustion resistant” CAR-T cells. In Aim 2, we will determine the contribution of NR4A regulated bZIP TFs to the function of NR4A-deficient CAR-T cells and their effects on transcriptional programs in “exhaustion resistant” CAR-T cells. In Aim 3, we will define the effects of NR4A TFs on bZIP TF activity at regulatory elements and identify chromatin associated co- factors that may be targeted to control the function of “exhaustion resistant” CAR-T cells. The expected outcome of our proposed studies is a comprehensive understanding of the effects of NR4A and bZIP TFs on CAR-T cells in tumors, through which we will identify practical strategies to “tune” the function of CAR-T cells for therapeutic benefit by controlling transcriptional programs.