SIRT1 negatively regulates the differentiation of IL-9-producing CD4+T cells. Mus musculus

Distinct metabolic programs support the differentiation of CD4+T cells into their separate lineages. In this study, we investigated metabolic mechanisms underlying the differentiation of IL-9 producing-CD4+T cells (TH9) in allergic airway inflammation and cancerous tumors. We found here that SIRT1 negatively regulates TH9 differentiation. A deficiency of SIRT1 induced by either conditional deletion in mouse CD4+T cells or the use of small interfering RNA (siRNA) in mouse or human T cells increased IL-9 production, whereas ectopic SIRT1 expression inhibited it. Notably, SIRT1-inhibited the differentiation of TH9 cells that regulated anti-tumor immunity and allergic pulmonary inflammation. Glycolytic activation through the mTOR-hypoxia-inducible factor-1α (HIF1α) pathway was required for the differentiation of the TH9 cells that confer protection against tumors and are involved in allergic airway inflammation. Our results define the essential features of a SIRT1-mTOR-HIF1α signaling-coupled glycolytic pathway in inducing TH9 cell differentiation, with implications for metabolic reprogramming as an immunotherapeutic approach. Overall design: Lymphocytes were isolated from the spleen and lymph nodes of mice and sorted on a FACSAria II (Becton Dickinson). The sorted naïve T cells (CD4+TCR+CD62Lhi CD44lo) from WT or SIRT1flox/flox-CD4-Cre mice were used for in vitro culture. T cells were activated with 2 ug/ml anti-CD3 (2C11; Bio X Cell), 2 ug/ml anti-CD28 (37.51; Bio X Cell) and 100 U/ml human IL-2. For TH9 cell differentiation, cultures were supplemented with 10 ng/ml IL-4 (R&D system), 2 ng/ml TGFβ1 (R&D system). After 5-6 d culture, differentiated T cells were collected and for microarray assay.