Effects of PGE2 on Reconstitution of Hematopoiesis and Immunity after UCBT

 描述（由申请人提供）：本修订申请基于标题为“PGE 2对脐带血移植（UCBT）后造血和免疫重建的影响”的原始RO 1申请（R 01 CA 183605 -01）。在过去的15个月里，我们进行了研究，以调查PGE 2在T细胞中的作用。使用微阵列基因表达分析，我们确定了一些基因被选择性改变的前列腺素E2在UCB T细胞。在转录因子NR 4A 2的表达上检测到最显著的效果。NR 4A转录因子最近已成为代谢功能的调节因子。利用ChIP-PCR技术，我们发现PGE 2诱导的NR 4A 2可以结合到肉毒碱棕榈酰转移酶（CPT 1A）的启动子上，从而上调CPT 1A的表达，增加T细胞中的脂肪酸氧化速率（FAO）。PGE 2还减少了葡萄糖转运蛋白Glut 1的表达和葡萄糖的摄取，这种作用在CD 8 + T细胞中更为突出。利用抗原特异性小鼠CD 8 + T细胞和T效应细胞和T记忆细胞体外分化的模型系统，我们发现PGE 2促进T记忆细胞的分化。我们还确定了前列腺素E2治疗脐带血移植物对病原体特异性和肿瘤特异性免疫有显著的临床影响。与对照UCBT接受者相比，PGE 2-UCBT接受者的EBV和CMV再活化发生率显著降低，白血病复发发生率降低。T细胞代谢重编程的差异对于有效地标记不同的T细胞命运至关重要。已经显示，向FAO的代谢转换促进CD 8 + T效应细胞向长寿T记忆细胞的转化。在各种T细胞实验系统中实施FAO诱导了记忆性CD 8 + T细胞数量的增加，并导致记忆性前体细胞TCM和TSCM细胞的产生，其显示出增强的抗肿瘤功能。综合我们关于PGE 2对T细胞代谢重编程和T记忆细胞发育的影响的体外发现，以及我们对PGE 2-UCBT接受者中免疫力改善的临床观察，表明PGE 2治疗可能通过介导肿瘤特异性T细胞的代谢重编程来改善抗肿瘤免疫力。这种方法可能代表了一种新的方法，以产生有效的肿瘤特异性T细胞的细胞为基础的肿瘤免疫治疗。为了解决这一假设，在本修订申请中，我们将追求以下具体目标：SA 1：确定PGE 2介导的代谢重编程的机制及其对肿瘤特异性T细胞的产生和功能的影响。A）确定PGE 2对肿瘤特异性小鼠T细胞的分子、代谢和基因表达程序以及对它们的体内抗肿瘤功能的影响。B）确定PGE 2对肿瘤特异性人T细胞的分子和代谢以及功能特性的影响。

 DESCRIPTION (provided by applicant): The present revision application is based on the original RO1 application entitled "Effects of PGE2 on reconstitution of hematopoiesis and immunity after umbilical cord blood transplantation (UCBT)" (R01 CA183605-01). During the past 15 months we performed studies to investigate the effects of PGE2 in T cells. Using microarray gene expression analysis we determined that a number of genes were selectively altered by PGE2 in UCB T cells. The most striking effect was detected on the expression of the transcription factor NR4A2. NR4A transcription factors have recently emerged as regulators of metabolic function. Using ChIP-PCR, we found that PGE2-induced NR4A2 could bind on the promoter of carnitine palmitoyltransferase (CPT1A), the rate limiting enzyme of fatty acid transport to the mitochondria, resulting in upregulation of CPT1A and increased rate of fatty acid oxidation (FAO) in T cells. PGE2 also diminished the expression of the glucose transporter Glut 1 and the uptake of glucose and this effect was more prominent in CD8+ T cells. Using antigen-specific mouse CD8+ T cells and a model system of in vitro differentiation of T effector and T memory cells, we found that PGE2 promoted T memory cell differentiation. We also determined that PGE2 treatment of the UCB grafts had a significant clinical impact on pathogen-specific and tumor-specific immunity. Compared to control UCBT recipients, PGE2-UCBT recipients had significantly reduced incidence of EBV and CMV reactivation, and reduced incidence of leukemia relapse. Divergence in the metabolic reprogramming of T cells is critical to effectively imprint distinct T cell fates. It has been shown that metabolic switch to FAO promotes the conversion of CD8+ T effector to long-lived T memory cells. Enforcing FAO in various T cell experimental systems induced increased numbers of memory CD8+ T cells and resulted in the generation of memory precursors, TCM and TSCM cells, which display enhanced anti-tumor function. Taken together our in vitro findings on the effects of PGE2 on T cell metabolic reprogramming and T memory cell development, and our clinical observations of improved immunity in PGE2-UCBT recipients suggest that PGE2 treatment might improve anti-tumor immunity by mediating metabolic reprogramming of tumor-specific T cells. This approach might represent a novel method to generate potent tumor-specific T cells for cell based tumor immunotherapy. To address this hypothesis in this revision application we will pursue the following specific aim to: SA1: Determine the mechanisms of PGE2-mediated metabolic reprogramming and its effects on the generation and function of tumor-specific T cells. A) To determine the effects of PGE2 on the molecular, metabolic and gene expression programs of tumor- specific mouse T cells and on their anti-tumor function in vivo. B) To determine the effects of PGE2 on the molecular and metabolic and functional properties of tumor-specific human T cells.