l-Leucine influx through Slc7a5 regulates inflammatory responses of human B cells via mammalian target of rapamycin complex 1 signaling
l-Leucine influx through Slc7a5 regulates inflammatory responses of human B cells via mammalian target of rapamycin complex 1 signaling
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DOI：
10.1080/14397595.2018.1510822
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发表时间：
2019-09-03
影响因子：
2.2
通讯作者：
Shibata, Hirotaka
中科院分区：
文献类型：
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作者：
Torigoe, Masataka;Maeshima, Keisuke;Shibata, Hirotaka
目的：越来越多的证据揭示了免疫细胞功能与其细胞内代谢之间的密切相关性。哺乳动物雷帕霉素靶蛋白复合物 1 (mTORC1) 是调节细胞活动的重要代谢调节信号。在某些类型的细胞中，mTORC1 的激活取决于 L-亮氨酸通过氨基酸转运蛋白 Slc7a5 的流入。然而，在 B 细胞中，Slc7a5 的表达和作用从未被研究过。方法：从健康成人的外周血中获得CD19(+) B细胞，并用Toll样受体9配体CpG寡脱氧核苷酸刺激。通过RT-PCR、流式细胞术和放射性同位素测定评估Slc7a5的表达和L-亮氨酸摄取。然后分析Slc7a5抑制对mTORC1活性、浆母细胞分化以及IgG和炎症细胞因子产生的影响。结果：CpG 刺激显着诱导 B 细胞中 Slc7a5 的表达，导致 L-亮氨酸流入。此外，抑制 Slc7a5 会消除 CpG 刺激的 B 细胞中的 mTORC1 激活、浆母细胞分化以及 IgG 和炎性细胞因子的产生。结论：L-亮氨酸通过 Slc7a5 流入可严格调节 mTORC1 活性和人类 B 细胞的免疫反应。 Slc7a5-mTORC1通路可能为自身免疫性疾病提供新的治疗策略。
Objectives: Increasing evidence has revealed the close correlation between immune cell functions and their intracellular metabolism. Mammalian target of rapamycin complex 1 (mTORC1) is the important metabolism-modulating signal that regulates cellular activities. In certain types of cell, it is known that mTORC1 activation depends on influx of l-leucine through an amino acid transporter, Slc7a5. In B cells, however, the expression and the role of Slc7a5 have never been investigated. Methods: CD19(+) B cells were obtained from peripheral blood of healthy adults and stimulated by a toll-like receptor 9 ligand, CpG oligodeoxynucleotides. The expression of Slc7a5 and l-leucine uptake were evaluated by RT-PCR, flow cytometry and radioisotope assay. Then the effect of Slc7a5 inhibition on mTORC1 activity, plasmablast differentiation and production of IgG and inflammatory cytokines were analyzed. Results: CpG stimulation significantly induced the expression of Slc7a5 in B cells, resulting in l-leucine influx. Furthermore, inhibition of Slc7a5 abrogated mTORC1 activation, plasmablast differentiation, and production of IgG and inflammatory cytokines in CpG-stimulated B cells. Conclusion: l-leucine influx through Slc7a5 critically regulates mTORC1 activity and the immunological responses of human B cells. Slc7a5-mTORC1 pathway may provide a novel therapeutic strategy for autoimmune diseases.