Therapeutic targeting of metabolic interactions between cancer and immune cells to improve the graft-versus-leukemia effect

急性髓系白血病(AML)是一种以骨髓中成髓细胞不受控制的增殖为特征的恶性疾病，导致大多数患者发生侵袭性的临床病程。AML的一种有效的治疗方案是异基因造血细胞移植(allo-HCT)，即来自外国捐赠者的同种异体反应性T细胞消除残留的白血病细胞。这个过程被称为移植物抗白血病效应(GVL)。然而，相当大比例的allo-HCT接受者会出现AML复发。急性髓细胞白血病复发可以通过供者淋巴细胞输注(DLI)联合细胞毒药物治疗，但这种方法的成功是有限的。导致AML细胞免疫逃逸的一个可能机制是细胞毒治疗和供体免疫系统的选择压力引起的代谢改变。识别哪些代谢途径被治疗存活的AML细胞使用可以为加强GVL效应提供新的靶点。在初步实验中，我观察到耐化疗的AML细胞在从细胞毒应激中恢复时重新连接他们的新陈代谢。这些细胞积累了几种代谢物，包括氨基己糖生物合成途径终点UDP-GlcNAc，这是蛋白质翻译后糖基化所必需的，以及能量丰富的代谢物肌酸和磷酸肌酸。基因表达分析和CRISPR-Cas9诱导的缺失模型的数据表明，细胞中肌酸丰度的增加是由于微环境摄取的增加。与此同时，我发现T细胞在效应器功能发育过程中也同样积累了肌酸，而删除肌酸转运蛋白SLC6A8会通过减少细胞因子的产生来损害T细胞的功能。在我的项目中，我将着重于以下目标：(I)探讨AML细胞和T细胞的肌酸代谢对GVL效应的影响；(Ii)测试氨基己糖生物合成途径和蛋白质糖基化调节增强GVL效应的可能性；(Iii)确定致癌突变和AML治疗类型对AML和T细胞之间代谢竞争的意义。我将通过使用体外技术和体内小鼠模型来实现这些目标。特定基因的作用将通过CRISPR-Cas9基因敲除和质粒介导的过度表达来研究。样品分析将通过液-质联用、RNA测序、流式细胞仪和功能代谢分析进行。该项目将得到我的东道主约翰霍普金斯大学医学院的埃里卡·皮尔斯教授的支持，他将提供科学专业知识和必要的技术设备。该项目旨在确定针对AML细胞和T淋巴细胞之间的代谢相互作用的新的药理学策略，最终目标是增强GVL效应并诱导AML的长期缓解。

Acute myeloid leukemia (AML) is a malignant disease characterized by an uncontrolled proliferation of myeloblasts in the bone marrow leading to an aggressive clinical course in most patients. One potent curative treatment option for AML is allogeneic hematopoietic cell transplantation (allo-HCT), in which alloreactive T cells from a foreign donor eliminate residual leukemia cells. This process is termed graft-versus-leukemia effect (GVL). However, a significant percentage of allo-HCT recipients develop an AML relapse. AML relapse can be treated by administering donor lymphocyte infusions (DLI) in combination with cytotoxic drugs, but the success of this approach is limited. One possible mechanism that leads to immune evasion of AML cells is an altered metabolism resulting from selection pressure by the cytotoxic treatment and the donor immune system. Recognizing which metabolic pathways are employed by therapy-surviving AML cells could offer novel targets to strengthen the GVL effect.In preliminary experiments I observed that chemotherapy-resistant AML cells rewired their metabolism during recovery from cytotoxic stress. These cells accumulated several metabolites, including hexosamine biosynthesis pathway endpoint UDP-GlcNAc, which is essential for post-translational glycosylation of proteins, as well as the energy-rich metabolites creatine and phosphocreatine. Data from gene expression analysis and CRISPR-Cas9-induced deletion models suggested that increased abundance of creatine in the cells was due to elevated uptake from the microenvironment. Simultaneously, I found that T cells likewise accumulated creatine during effector function development and that deleting the creatine transporter SLC6A8 impaired T cell function by reducing cytokine production. In my project, I will focus on following aims: (i) to explore the impact of creatine metabolism in AML cells and T cells on the GVL effect; (ii) to test the potential of modulations in the hexosamine biosynthesis pathway and protein glycosylation for enhancement of the GVL effect; (iii) to determine the significance of oncogenic mutations and the type of AML treatment on metabolic competition between AML and T cells. I will achieve these objectives by using in vitro techniques and in vivo mouse models. The role of specific genes will be studied by CRISPR-Cas9-incuded knockdown and plasmid-mediated overexpression. Sample analysis will be performed by liquid-chromatography-mass spectrometry, RNA sequencing, flow cytometry and functional metabolic assays. The project will be supported by my host, Prof. Erika Pearce at the Johns Hopkins University School of Medicine, who will provide scientific expertise and the necessary technical equipment. This project aims to identify novel pharmacological strategies that target metabolic interactions between AML cells and T lymphocytes with the ultimate goal to boost the GVL effect and induce long-lasting AML remissions.