Transcriptional Control of T Cell Function

项目摘要 对癌症应答的T细胞发展出低应答表型，其特征在于高水平的抑制性T细胞增殖。 受体表达、低细胞因子产生和不能控制肿瘤生长。我们先前已经确定 由小鼠和人类T细胞共享的持续抗原刺激诱导的转录程序 对慢性病毒感染和肿瘤的反应。我们将这个程序与核受体的激活联系起来， 亚家族4 A组（NR 4A）转录因子（TF），在慢性刺激期间被有效诱导。 我们还确定了NR 4A敏感的调节元件，这些元件在对慢性炎症反应的T细胞中变得容易接近。 病毒感染和肿瘤。我们发现NR 4A转录因子同时促进抑制性受体的表达， 有限的细胞因子产生，导致耗尽的T细胞状态，减少嵌合抗原受体 表达针对实体瘤的T（CAR-T）细胞活性。CAR-T细胞被工程化以缺乏所有三种NR 4A TF 与野生型T细胞相比，T细胞分化为具有强效抗肿瘤活性的独特群体。我们连线 这改善了在NR 4A缺陷型小鼠中碱性亮氨酸拉链（bZIP）TF的表达和活性增加的功能， T细胞比野生型。在新的初步研究中，我们发现NR 4A TF部分缺失的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“抗耗竭”表型 这些细胞具有效应子功能，并具有增加的长期存活潜力。在本申请中，我们 将测试NR 4A和bZIP TF可以被“调整”以控制转录程序的假设， “抗耗竭”CAR-T细胞在肿瘤中的功能。在目标1中，我们将确定 使用抗体或小分子对“抗耗竭”CAR-T的功能和存活进行干预 细胞在目标2中，我们将确定NR 4A调节的bZIP TF对NR 4A缺陷的bZIP TF的功能的贡献。 CAR-T细胞及其对“抗耗竭”CAR-T细胞中转录程序的影响。在目标3中，我们 确定NR 4A TF对bZIP TF活性在调控元件上的作用，并鉴定染色质相关的共- 这些因子可以被靶向以控制“抗耗竭”CAR-T细胞的功能。预期结果 我们提出的研究之一是全面了解NR 4A和bZIP TF对CAR-T细胞的影响 通过这些研究，我们将确定实用的策略来“调整”CAR-T细胞的功能， 通过控制转录程序而受益。

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.