Plasticity of human gamma/delta T cells: Modulation by Vitamin C

在24个月的第一个资助期内，我们证明了维生素C（VitC）显著增加了人类γ/δ T细胞的激活和效应功能。VitC增加γ/δ T细胞的增殖活性、代谢活性和细胞因子产生。然而，我们还发现，维生素C，在额外存在的转化生长因子-β（TGF-β），上调转录因子FOXP 3的表达，并诱导抑制活性的人γ/δ T细胞，与强烈的低甲基化在特定区域的FOXP 3基因。通过RNAseq和全基因组甲基化研究进行的转录组分析确定了人类γ/δ T细胞中VitC调控基因的几个候选者。我们还参与了一项临床I期研究，其中将在VitC存在下扩增的同种异体γ/δ T细胞过继转移到癌症患者中。第一个资助期的结果已发表在三篇原创论文中。基于这些结果，本更新提案的目标是进一步研究VitC对人γ/δ T细胞可塑性的影响。我们将集中在以下研究问题：（1）VC如何调节γ/δ T细胞中的T细胞受体信号传导，以及我们以前的研究中发现的一些VitC调节基因的意义;（2）VitC如何增加γ/δ T细胞的细胞毒性效应功能？(3)维生素C如何与其他临床相关的表观遗传修饰剂如组蛋白脱乙酰酶抑制剂联合调节人γ/δ T细胞的激活和效应功能？该项目的总体目标是优化人γ/δ T细胞的效应子功能，以应用于细胞免疫治疗。

During the first funding period of 24 months, we demonstrated that Vitamin C (VitC) increases significantly the activation and effector functions of human gamma/delta T cells. VitC increases the proliferative activity, the metabolic activity, and the cytokine production in gamma/delta T cells. However, we also showed that VitC, in the additional presence of transforming growth factor-beta (TGF-beta), upregulates the expression of the transcription factor FOXP3 and induces suppressive activity in human gamma/delta T cells, associated with strong hypomethylation in specific regions of the FOXP3 gene. Transcriptome analysis performed by RNAseq and genome-wide methylation studies identified several candidates of VitC-regulated genes in human gamma/delta T cells. We also contributed to a clinical phase I study where allogeneic gamma/delta T cells expanded in presence of VitC were adoptively transferred into cancer patients. The results of the first funding period have been published in three original papers. Based on these results, the goal of the present renewal proposal is to investigate further the influence of VitC on the plasticity of human gamma/delta T cells. We will focus on the following research questions: (1) How does VC modulate T-cell receptor signaling in gamma/delta T cells and what is the significance of some of the VitC-regulated genes identified in our previous studies; (2) how does VitC increase the cytotoxic effector function of gamma/delta T cells? (3) How does VitC in combination with other, clinically relevant epigenetic modifiers such as histone deacetylase inhibitors modulate the activation and effector functions of human gamma/delta T cells? The overall goal of this project is to optimize the effector function of human gamma/delta T cells for application in cellular immunotherapy.