Wu Di, Chen Qiuxu, Tan Mingjia, Sun Yi
Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education) of the Second Affiliated Hospital, and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou 310029, China.
Cancer Center of Zhejiang University, Hangzhou 310029, China.
Research (Wash D C). 2025 Jul 10;8:0774. doi: 10.34133/research.0774. eCollection 2025.
T lymphocytes consist of αβ and γδ T cells, which mature and differentiate from the same progenitor cells in the thymus. Cullin-RING ligases (CRLs), the largest family of ubiquitin ligases, require neddylation on the scaffold protein Cullins for their ligase activity. The role of neddylation-CRL system in thymus development and fate determination of αβ/γδ T cells remains elusive. Here, we generated conditional knockout mouse models with thymus individual deletion of Ube2m or Ube2f, 2 neddylation E2-conjugating enzymes, and Rbx1 or Sag, 2 dual neddylation and ubiquitylation E3 ligases. We found that only Rbx1, but not Ube2m/Ube2f, nor Sag, plays an essential role in thymus development and fate determination of αβ/γδ T cells. Specifically, Rbx1 loss causes shrinkage of the thymus, delayed T cell development, increased γδ T cells in the thymus, increased the ratio of immature γδ T cells, and decreased the ratio of the proliferative subpopulation. Some of these phenotypes were moderately rescued by simultaneous Bim deletion. Mechanistically, Rbx1 loss alters the Akt, NF-κB, and metabolic pathways in progenitor γδ T cells/DN3a cells. Finally, loss altered the γδ T1/T17 cell population in the thymus, suggesting that Rbx1 controls the fate of γδ T cells.
T淋巴细胞由αβ和γδ T细胞组成，它们在胸腺中由相同的祖细胞成熟并分化。Cullin-RING连接酶（CRLs）是泛素连接酶中最大的家族，其连接酶活性需要在支架蛋白Cullin上进行NEDD化修饰。NEDD化-CRL系统在胸腺发育以及αβ/γδ T细胞命运决定中的作用仍不清楚。在此，我们构建了条件性敲除小鼠模型，分别在胸腺中特异性敲除2种NEDD化E2结合酶Ube2m或Ube2f，以及2种双重NEDD化和泛素化E3连接酶Rbx1或Sag。我们发现，在αβ/γδ T细胞的胸腺发育和命运决定中，只有Rbx1发挥关键作用，而Ube2m/Ube2f和Sag则不然。具体而言，Rbx1缺失会导致胸腺萎缩、T细胞发育延迟、胸腺中γδ T细胞增多、未成熟γδ T细胞比例增加以及增殖亚群比例降低。同时缺失Bim可部分挽救其中一些表型。从机制上讲，Rbx1缺失会改变祖代γδ T细胞/DN3a细胞中的Akt、NF-κB和代谢途径。最后，Rbx1缺失改变了胸腺中γδ T1/T17细胞群体，这表明Rbx1控制着γδ T细胞的命运。
