Natural killer cells and immune control: Deciphering the transcription factors that regulate expression of the NKG2D-ligand MICA

自然杀伤细胞和免疫控制：破译调节 NKG2D 配体 MICA 表达的转录因子

• 批准号: 324329506
• 负责人: Professorin Dr. Elke Pogge von Strandmann
• 金额: --
• 依托单位: Zentrum für Tumor- und Immunbiologie (ZTI)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/324329506?language=en
• 关键词: Natural; killer; cells; immune; control

NKG2D (encoded by the KLRK1 gene, killer cell lectin-like receptor subfamily K, member 1) is a C-type lectin receptor and an important activating immunoreceptor involved in tumor surveillance. NKG2D is expressed on the surface of most cytotoxic lymphocytes such as NK cells, CD8+ T cells, some γδ T cells, and possibly also some CD4+ T cells and known as a sensor for damaged or dangerous cells. Ligands for NKG2D (NKG2D-L) are generally not expressed on healthy cells but are induced on the surface of malignant cells. Evasion from the innate NKG2D-mediated immune surveillance is a hallmark of many solid and hematopoietic tumors and depends among other strategies on proteolytic shedding and release of soluble NKG2D-L. This renders target cells invisible to an NKG2D-dependent NK cell attack and moreover causes a downregulation of receptor surface expression on effector cells. Targeting the NKG2D-NKG2D-L axis to stimulate anti-tumor immunity is a promising therapeutic approach. Here, we aim to identify specific transcription factors, which regulate the inducible expression of MHC Class I Polypeptide-Related Sequence A (NKG2D-L, MICA). Until today the network of transcription factors regulating the up-regulation of MICA is not defined. A better understanding of factors that direct NKG2D-L expression will contribute to the development of novel therapeutic strategies aiming at an increased NKG2D-L expression on the tumor cell surface and thus more efficient killing by NK cells. In our previous work, we demonstrated that CBP/p300 acetyltransferases and the cAMP responsive element binding protein (CREB) contribute critically to the inducible expression of MICA. Using an enChIP approach we identified several transcription factors which are in response to histone deacetylase inhibition associated with the active MICA promoter including Krüppel-like factor 4 (KLF4), Yin Yang 1 (YY1), and CCCTC-Binding Factor (CTCF). The aim of this project is to assess the involvement of these candidate proteins, in particular transcription factors, in the regulation of MICA expression. For this purpose, we plan to analyze to what extend these factors regulate the transcription of MICA in promoter-reporter assays. Further overexpression and depletion approaches are planned to investigate the impact on MICA surface protein expression and on NK cell-mediated target cell elimination. Finally the clinical relevance of the identified factors will be assessed in acute myeloma leukemia patient samples. To this end we will perform Rhapsodytm (Beckman Coulter) single-cell sequencing to correlate MICA and candidate factor expression and to measure whether these factors regulate (gain/loss of function) MICA expression and susceptibility against NK cells. We expect that we will identify positive regulators of MICA which may on the long run represent novel therapeutic targets.

NKG2D（由KLRK1基因编码，杀伤细胞凝集素样亚家族K，成员1）是C型凝集素受体，重要的是参与肿瘤监测的重要activatin noeceptor。细胞，CD8+ T细胞，某些γδT细胞，并且可能在健康细胞上表达一些CD4+ D-L），而是在恶性细胞的表面上诱导的。并取决于蛋白水解脱落和可溶性NKG2D-L的释放。治疗方法。肿瘤细胞表面，从而通过NK细胞效率更高，我们证明了CBP/P300乙酰基转移酶和CAMP反应式结合蛋白（CREB）对与云母的诱导表达有很大的影响。因子4（KLF4），Yin Yang 1（YY1）和CCCTC结合因子（CTCF）。这些因素扩展了启动子 - 培养剂测定中的云母的转录。功能）云母表达和对NK细胞的敏感性。