IDH mutations in the interplay of metabolism and antileikemic immune response

细胞毒性T淋巴细胞（CTL）的连续转移以及白血病抗原的疫苗接种是有效的策略，以提高对白血病的免疫监视。最近，在高达20%的患者的急性髓性白血病（AML）原始细胞中检测到编码代谢酶异柠檬酸脱氢酶（IDH）1和2的基因突变（Mut）。IDH突变诱导新形态功能以产生癌代谢物2-羟基戊二酸（2-HG），其可在抑制α-酮戊二酸依赖性双加氧酶（例如DNA脱甲基酶）后改变许多细胞过程。我们先前已经建立了体外方案，以在用患者来源的原代白血病细胞刺激后，从HLA匹配的初始T细胞前体可靠地产生白血病反应性CD 4+和CD 8 + CTL。在提交的项目中，我们将研究针对IDHMut 1和2的T细胞应答。为此，我们将刺激来自AML患者和健康供体的CD 4+和CD 8 + T细胞对抗IDHMut蛋白和预测的IDHMut肽表位。为了分析IDHMut特异性T细胞的生物学相关性，我们将T细胞克隆过继转移到AML移植的免疫缺陷NOD/SCID/IL 2 Rgcnull（NSG）小鼠中。在第二部分中，我们将研究2-HG对人树突状细胞（DC）和T细胞的影响。在此，我们的初步数据显示，2-HG降低DC中IL-12的分泌，这可能损害T细胞活化。将进一步分析这种效应的潜在机制（例如细胞因子分泌的转录调节）。我们的假设是IDHMut特异性T细胞是IDHMut + AML过继免疫治疗中的有效白血病特异性效应子。白血病原始细胞的特异性消除也会降低患者的2-HG水平，这可能会进一步增强抗白血病免疫力。

Adoptive transfer of cytotoxic T lymphocytes (CTL) as well as vaccination with leukemia antigens are potent strategies to improve immunosurveillance against leukemias. Recently, mutations (Mut) in the genes encoding the metabolic enzymes isocitrate dehydrogenase (IDH) 1 and 2 have been detected in acute myeloid leukemia (AML) blasts of up to 20% of patients. IDH mutations induce a neomorphic function to produce the oncometabolite 2-hydroxyglutarate (2-HG), which can alter many cellular processes upon inhibition of a-ketoglutarate dependent dioxygenases (e.g. DNA demethylases). We have previously established in vitro protocols to reliably generate leukemia reactive CD4+ and CD8+ CTL from HLA-matched naive T-cell precursors upon stimulation with patient-derived primary leukemia cells. In the submitted project we will investigate T-cell responses against IDHMut 1 and 2. For this, we will stimulate CD4+ and CD8+ T cells from AML patients and healthy donors against IDHMut proteins and predicted IDHMut peptide epitopes. To analyze the biological relevance of IDHMut specific T cells, we will adoptively transfer T-cell clones into AML engrafted immunodeficient NOD/SCID/IL2Rgcnull (NSG) mice. In the second part of the project, we will investigate the effect of 2-HG on human dendritic cells (DC) and T cells. Here, our preliminary data show that 2-HG decreases the secretion of IL-12 in DCs, which possibly impairs T-cell activation. The underlying mechanism of this effect will be further analyzed (e.g. transcriptional regulation of cytokine secretion). Our hypothesis is that IDHMut specific T cells are potent leukemia-specific effectors in adoptive immunotherapy of IDHMut + AML. Specific elimination of leukemia blasts would also reduce 2-HG levels in patients, which potentially would further strengthen antileukemia immunity.