成熟T/NK细胞肿瘤常见于东亚且多伴EB病毒感染，遗传背景复杂、病情进展迅速。申请者前期下一代测序发现：约24%的成熟T/NK细胞肿瘤存在HLH相关基因杂合突变，以参与细胞毒颗粒运输及释放的重要基因UNC13D的G863D突变最为常见。基于此，我们提出假说：UNC13D等HLH相关基因杂合突变，可导致患者细胞毒性淋巴细胞（CL）抗病毒及肿瘤免疫异常，从而促进成熟T/NK细胞肿瘤的发生发展。本项目拟结合本中心已有的EBV相关T/NK淋巴瘤转基因模式小鼠，采用CRISPR/Cas9技术构建UNC13D基因杂合突变的成熟NK、CAR-T细胞模型和该基因敲减的动物模型，探索此类突变对CL的细胞毒功能影响及与成熟T/NK细胞肿瘤发生发展的相关性，并通过下一代测序在患者中大规模验证及筛查HLH相关基因突变。本项目将阐明遗传学基因异常与成熟T/NK细胞肿瘤进展的全新机制，为疾病防治决策提供新的方向。

Mature T/NK-cell neoplasms are a group of highly aggressive Epstein-Barr virus (EBV)-associated lymphoid malignancies with complex genomic alterations, which are notably more prevalent in East Asia. Our previous next-generation sequencing (NGS) study revealed that approximately 24% patients with mature T/NK-cell neoplasms harbored heterozygous mutations in hemophagocytic lymphohistiocytosis (HLH)-associated genes, among which a missense mutation p.Gly863Asp in UNC13D had the highest frequency. The protein coded by UNC13D plays an important role in the pathway of cytotoxic granules vesicle trafficking and releasing. Thus, we hypothesize that monoallelic mutation in UNC13D and other HLH-related genes would lead to abnormal anti-virus and tumor immunity, and promote the initiation and progression of mature T/NK-cell neoplasm. Combined with the EBV-related T/NK-cell lymphoma transgenic mouse model we have already established, we will make UNC13D-mutated mature NK and CAR-T cell models and UNC13D knock-down mouse model by CRISPR/Cas9 technic. We are aiming to explore how monoallelic mutations in HLH-related genes impair the function of cytotoxic lymphocytes and their relationship with mature T/NK-cell tumorigenesis. We will also screen HLH-associated mutations in a large number of mature T/NK lymphoma patients using our NGS platform. Our study will provide novel insight in prevention and therapy of mature T/NK-cell neoplasms.