Human cytomegalovirus-mediated modulation of leukemia and its immune control by donor T cell alloreactivity to HLA-DPB1 after hematopoietic stem cell transplantation

人巨细胞病毒介导的白血病调节及其造血干细胞移植后供体 T 细胞对 HLA-DPB1 同种异体反应性的免疫控制

• 批准号: 423291167
• 负责人: Professorin Dr. Katharina Fleischhauer
• 金额: --
• 依托单位: Institut für Virologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/423291167?language=en
• 关键词: Human; cytomegalovirus; mediated; modulation; leukemia

Human cytomegalovirus (HCMV) is a prototypical β-herpesvirus with important clinical relevance, especially for immunosuppressed patients like individuals receiving allogeneic hematopoietic stem cell transplantation (HSCT) as curative therapy for leukemia. In this setting, HCMV reactivation has been shown to impact both immune reconstitution and the risk of developing graft versus host disease (GvHD) or relapse after transplantation. Three novel, mutually non-exclusive hypotheses to explain these clinical observations will be explored during the proposed project, through the synergistic effort of the two PIs who will contribute their complementary expertise in the immunobiology of HSCT and cytomegaloviruses, respectively: 1) Heterologous immunity by HCMV-specific CD4+ T cell receptors (TCR) cross-recognizing HLA-DPB1 alloantigens (mainly PI Fleischhauer). HCMV-specific and HLA-DPB1 alloreactive CD4+ T cell cultures will be independently obtained from donors of HLA-DPB1-mismatched unrelated HSCT at UK-Essen. Their TCR CDR3 sequences will be determined by next generation sequencing. TCR with identical CDR3 sequences identified in both cultures are indicative of heterologous immunity and will be longitudinally traced in the patient with or without acute GvHD or leukemia relapse after transplantation. 2) HCMV-encoded proteins modulating the immunogenicity of allogeneic HLA-DPB1 (PI Fleischhauer and Trilling). An available library of expression vectors covering the canonical HCMV proteins will be introduced individually into single HLA-DP expressing model cell lines, to test the gene-specific impact on allorecognition by HLA-DPB1-specific CD4+ T cells. Identified candidate genes will be characterized concerning their effects on HLA-DPB1 expression and processing upon ectopic expression as well as in the context of HCMV infection. 3) Cellular and viral determinants of the HCMV-induced impairment of leukemic cell proliferation (mainly PI Trilling). To identify and characterize the mediators of previously observed anti-proliferative effects elicited by inactivated HCMV particles on acute myeoloid leukemia (AML) cells, a series of biochemical and immunological assays as well as inhibition studies will be conducted to test the hypothesis that HCMV triggers a suicidal innate immune response after contact with AML cells, and to identify the responsible factors. Together, the new insights into the immunobiology of T cell alloreactivity, HCMV and leukemia expected from this project will have potential translational implications in cellular therapy.

人巨细胞病毒是一种典型的β疱疹病毒，具有重要的临床意义，尤其是对免疫功能低下的患者，如接受异基因造血干细胞移植治疗白血病的患者。在这种情况下，HCMV的重新激活已被证明影响免疫重建和发生移植物抗宿主病(GvHD)或移植后复发的风险。在拟议的项目中，通过两个PI的协同努力，将探索三个新的、相互非排他性的假设来解释这些临床观察，这两个PI将分别在HSCT和巨细胞病毒的免疫生物学方面贡献他们的互补专业知识：1)HCMV特异性CD4+T细胞受体(TCR)交叉识别HLA-DPB1同种抗原(主要是Pi Fleischhauer)的异种免疫。人类巨细胞病毒特异性和人类白细胞抗原DPB1同种异体反应性的CD4+T细胞培养将从英国埃森的人类白细胞抗原DPB1不匹配的非血缘关系造血干细胞移植的供者那里独立获得。他们的TCR CDR3序列将通过下一代测序确定。在两种培养物中发现相同CDR3序列的TCR表明异种免疫，并将在移植后有或无急性移植物抗宿主病或白血病复发的患者中进行纵向追踪。2)调节同种异体人类白细胞抗原-DPB1免疫原性的HCMV编码蛋白(PI、Fleischhauer和Trling)。现有的涵盖典型HCMV蛋白的表达载体文库将单独引入单个人类白细胞抗原-DP表达模型细胞系，以测试基因特异性对人类白细胞抗原-DPB1特异性CD4+T细胞识别同种异体的影响。已确定的候选基因将根据它们对人类白细胞抗原-DPB1表达的影响和对异位表达的处理以及在巨细胞病毒感染的背景下进行表征。3)巨细胞病毒诱导白血病细胞增殖障碍的细胞和病毒决定因素(主要是PI-Trilling)。为了鉴定和表征灭活的巨细胞病毒颗粒对急性粒细胞白血病(AML)细胞的抗增殖作用的介体，将进行一系列的生化和免疫学检测以及抑制研究，以验证HCMV与AML细胞接触后触发自杀性天然免疫反应的假说，并确定其相关因素。总之，该项目对T细胞同种异体反应性、巨细胞病毒和白血病的免疫生物学的新见解将在细胞治疗中具有潜在的翻译意义。