期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:2016
卷号:113
期号:27
页码:7596-7601
DOI:10.1073/pnas.1600934113
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:Type 2 phosphatidylinositol-5-phosphate 4-kinase (PI5P4K) converts phosphatidylinositol-5-phosphate to phosphatidylinositol-4,5-bisphosphate. Mammals have three enzymes PI5P4Kα, PI5P4Kβ, and PI5P4Kγ, and these enzymes have been implicated in metabolic control, growth control, and a variety of stress responses. Here, we show that mice with germline deletion of type 2 phosphatidylinositol-5-phosphate 4-kinase gamma (Pip4k2c), the gene encoding PI5P4Kγ, appear normal in regard to growth and viability but have increased inflammation and T-cell activation as they age. Immune cell infiltrates increased in Pip4k2c−/− mouse tissues. Also, there was an increase in proinflammatory cytokines, including IFNγ, interleukin 12, and interleukin 2 in plasma of Pip4k2c−/− mice. Pip4k2c−/− mice had an increase in T-helper-cell populations and a decrease in regulatory T-cell populations with increased proliferation of T cells. Interestingly, mammalian target of rapamycin complex 1 (mTORC1) signaling was hyperactivated in several tissues from Pip4k2c−/− mice and treating Pip4k2c−/− mice with rapamycin reduced the inflammatory phenotype, resulting in a decrease in mTORC1 signaling in tissues and a decrease in proinflammatory cytokines in plasma. These results indicate that PI5P4Kγ plays a role in the regulation of the immune system via mTORC1 signaling.