IDH mutations in the interplay of metabolism and antileikemic immune response

细胞毒性T淋巴细胞（CTL）的过继转移以及白血病抗原疫苗接种是提高对白血病免疫监测的有效策略。最近，编码代谢酶异柠檬酸脱氢酶（IDH） 1和2的基因突变（Mut）在高达20%的急性髓性白血病（AML）患者中被检测到。IDH突变诱导产生肿瘤代谢物2-羟基戊二酸（2-HG）的新形态功能，它可以通过抑制a-酮戊二酸依赖的双加氧酶（例如DNA去甲基化酶）来改变许多细胞过程。我们之前已经建立了体外方案，在患者来源的原发性白血病细胞刺激下，从hla匹配的幼稚t细胞前体中可靠地产生白血病反应性CD4+和CD8+ CTL。在提交的项目中，我们将研究t细胞对IDHMut 1和2的反应。为此，我们将刺激来自AML患者和健康供体的CD4+和CD8+ T细胞对抗IDHMut蛋白，并预测IDHMut肽表位。为了分析IDHMut特异性T细胞的生物学相关性，我们将过继性地将T细胞克隆转移到AML移植的免疫缺陷NOD/SCID/ il2rgnull （NSG）小鼠中。在项目的第二部分，我们将研究2-HG对人类树突状细胞（DC）和T细胞的影响。在这里，我们的初步数据显示，2-HG降低了dc中IL-12的分泌，这可能会损害t细胞的活化。这种效应的潜在机制将进一步分析（如细胞因子分泌的转录调节）。我们的假设是IDHMut特异性T细胞在IDHMut + AML的过继免疫治疗中是有效的白血病特异性效应物。特异性消除白血病原细胞也会降低患者的2-HG水平，这可能会进一步增强抗白血病免疫。

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.