The First Affiliated Hospital, Biomedical Translational Research Institute, Guangdong Province Key Laboratory of Molecular Immunology and Antibody Engineering, Jinan University, Guangzhou, China.
School of Medicine and Institute for Immunology, Beijing Key Lab for Immunological Research on Chronic Diseases, Tsinghua University, Beijing, 100084, China.
Cell Death Differ. 2019 Oct;26(10):1918-1928. doi: 10.1038/s41418-018-0263-8. Epub 2019 Jan 8.
Phosphoinositide-dependent kinase-1 (PDK1) is an important enzyme for immune cell development by connecting PI3K to downstream mTOR signaling. It is needed to investigate how PDK1 spatiotemporally orchestrates NK cells development and whether this kinase is required for NK cells effector function. In this study, we used three genetic models to delete pdk1 at respective developmental stages, including hematopoietic stem cells (Vav1-Cre used), NK cell progenitor (NKp, CD122-Cre used) and terminal NK cells (Ncr1-Cre used). We found that CD122-Cre mediated deletion of pdk1 caused a severe loss of NK cells to an extent comparable to that of deletion by Vav1-Cre, and further revealed that PDK1 was necessary for NK cells master transcription factor E4BP4 expression at the NKp stage. Moreover, Ncr1-Cre-mediated inactivation of pdk1 delayed NK cells terminal differentiation. These PDK1-deficient NK cells secreted decreased amounts of the cytokine IFN-γ, likely due to impaired downstream mTOR activation. They also exhibited reduced degranulation in response to tumor cells. Mechanistically, PDK1 was critical for the formation of NK-target conjugates and lytic synapses. Therefore, we clarify the stage-specific roles of the metabolic regulator PDK1 in NK cells biology.
磷酸肌醇依赖激酶-1（PDK1）是一种将 PI3K 连接到下游 mTOR 信号的重要酶，对于免疫细胞的发育至关重要。我们需要研究 PDK1 如何在空间和时间上协调 NK 细胞的发育，以及该激酶是否对 NK 细胞的效应功能有要求。在这项研究中，我们使用三种遗传模型在各自的发育阶段敲除 pdk1，包括造血干细胞（使用 Vav1-Cre）、NK 细胞前体（使用 NKp，CD122-Cre）和终末 NK 细胞（使用 Ncr1-Cre）。我们发现 CD122-Cre 介导的 pdk1 缺失导致 NK 细胞严重缺失，其程度与 Vav1-Cre 介导的缺失相当，进一步表明 PDK1 对于 NKp 阶段 NK 细胞主转录因子 E4BP4 的表达是必需的。此外，Ncr1-Cre 介导的 pdk1 失活延迟了 NK 细胞的终末分化。这些 PDK1 缺陷型 NK 细胞分泌的细胞因子 IFN-γ 减少，可能是由于下游 mTOR 激活受损所致。它们对肿瘤细胞的脱粒反应也减少。从机制上讲，PDK1 对于 NK 细胞与靶细胞的共轭和溶酶体突触的形成至关重要。因此，我们阐明了代谢调节剂 PDK1 在 NK 细胞生物学中的特定阶段作用。
