Cancer Research Cluster, Saskatchewan Cancer Agency, 20 Campus Drive, Saskatoon, SK S7N 4H4, Canada.
Division of Oncology, College of Medicine, University of Saskatchewan, 107 Wiggins Road, Saskatoon, SK S7N 5E5, Canada.
Int J Mol Sci. 2022 Aug 23;23(17):9534. doi: 10.3390/ijms23179534.
Two common γ-chain family cytokines IL-2 and IL-15 stimulate the same mammalian target of rapamycin complex-1 (mTORC1) signaling yet induce effector T (T) and memory T (T) cell differentiation via a poorly understood mechanism(s). Here, we prepared in vitro IL-2-stimulated T (IL-2/T) and IL-15-stimulated T (IL-15/T) cells for characterization by flow cytometry, Western blotting, confocal microscopy and Seahorse-assay analyses. We demonstrate that IL-2 and IL-15 stimulate strong and weak mTORC1 signals, respectively, which lead to the formation of CD62 ligand (CD62L) killer cell lectin-like receptor subfamily G member-1 (KLRG) IL-2/T and CD62LKLRG IL-15/T cells with short- and long-term survival following their adoptive transfer into mice. The IL-15/mTORC1 signal activates the forkhead box-O-1 (FOXO1), T cell factor-1 (TCF1) and Eomes transcriptional network and the metabolic adenosine monophosphate-activated protein kinase-α-1 (AMPKα1), Unc-51-like autophagy-activating kinase-1 (ULK1) and autophagy-related gene-7 (ATG7) axis, increasing the expression of mitochondrial regulators aquaporin-9 (AQP9), mitochondrial transcription factor-A (TFAM), peroxisome proliferator-activated receptor-γ coactivator-1α (PGC1α), carnitine palmitoyl transferase-1 (CPT1α), microtubule-associated protein light chain-3 II (LC3II), Complex I and ortic atrophy-1 (OPA1), leading to promoting mitochondrial biogenesis and fatty-acid oxidation (FAO). Interestingly, AMPKα1 deficiency abrogates these downstream responses to IL-15/mTORC1 signaling, leading to the upregulation of mTORC1 and hypoxia-inducible factor-1α (HIF-1α), a metabolic switch from FAO to glycolysis and reduced cell survival. Taken together, our data demonstrate that IL-15/mTORC1 signaling controls T-cell memory via activation of the transcriptional FOXO1-TCF1-Eomes and metabolic AMPKα1-ULK1-ATG7 pathways, a finding that may greatly impact the development of efficient vaccines and immunotherapies for the treatment of cancer and infectious diseases.
两种常见的 γ 链家族细胞因子 IL-2 和 IL-15 刺激相同的哺乳动物雷帕霉素靶蛋白复合物 1（mTORC1）信号，但通过一种了解甚少的机制诱导效应 T（T）和记忆 T（T）细胞分化。在这里，我们通过流式细胞术、Western blot、共聚焦显微镜和 Seahorse 分析制备了体外 IL-2 刺激的 T（IL-2/T）和 IL-15 刺激的 T（IL-15/T）细胞进行表征。我们证明，IL-2 和 IL-15 分别刺激强和弱的 mTORC1 信号，这导致形成 CD62 配体（CD62L）杀伤细胞凝集素样受体亚家族 G 成员 1（KLRG）IL-2/T 和 CD62LKLRG IL-15/T 细胞，在其被过继转移到小鼠后具有短期和长期生存能力。IL-15/mTORC1 信号激活叉头框 O-1（FOXO1）、T 细胞因子-1（TCF1）和 Eomes 转录网络以及代谢腺苷单磷酸激活蛋白激酶-α-1（AMPKα1）、未结合 1 样自噬激活激酶-1（ULK1）和自噬相关基因-7（ATG7）轴，增加线粒体调节剂水通道蛋白-9（AQP9）、线粒体转录因子-A（TFAM）、过氧化物酶体增殖物激活受体-γ 共激活因子-1α（PGC1α）、肉毒碱棕榈酰转移酶-1（CPT1α）、微管相关蛋白轻链 3 II（LC3II）、复合物 I 和 ortic 萎缩-1（OPA1）的表达，促进线粒体生物发生和脂肪酸氧化（FAO）。有趣的是，AMPKα1 缺乏会破坏这些对 IL-15/mTORC1 信号的下游反应，导致 mTORC1 和缺氧诱导因子-1α（HIF-1α）的上调，这是从 FAO 到糖酵解的代谢转换和细胞存活率降低。总之，我们的数据表明，IL-15/mTORC1 信号通过激活转录 FOXO1-TCF1-Eomes 和代谢 AMPKα1-ULK1-ATG7 途径来控制 T 细胞记忆，这一发现可能会极大地影响高效疫苗和免疫疗法的发展，以治疗癌症和传染病。
