STING activation induces inhibition of the mTORC1 pathway. STING activation induces inhibition of the mTORC1 pathway. (A) Naive CD4+ T cells were stimulated with anti-CD3/CD28 Abs in the presence or absence of cGAMP for 15 h, and IL-2 production was assessed by ELISA. (B) Naive CD4+ T cells were stimulated with anti-CD3/CD28 Abs in the presence or absence of exogenously added IL-2 (100 ng/ml) and cGAMP, and cell growth was assessed by a WST-8 cell proliferation assay. (C) Western blot analysis of CD4+ T cells stimulated with anti-CD3/CD28 Abs in the presence or absence of cGAMP and IL-2 (100 ng/ml) or anti-IL-2R Ab. (D) Naive CD4+ T cells were stimulated with anti-CD3/CD28 Abs in the presence or absence of anti-IL-2R Ab or cGAMP, and cell growth was assessed by a WST-8 cell proliferation assay. (E) Western blot analysis for activation of mTOR signaling in CD4+ T cells stimulated with anti-CD3/CD28 Abs in the presence or absence of different STING ligands, cGAMP, c-di-AMP, or DMXAA. (F) qPCR analysis for the expression of various genes in CD4+ T cells from Rptor+/+ (closed column) or Rptor-fl/fl (open column) mice stimulated with anti-CD3/CD28 Abs with or without cGAMP for 24 h. Data are the mean from duplicate (A, B) or triplicate (F) ± SD. Data are representative of at least three independent experiments (A–F). Takayuki Imanishi et al. LSA 2019;2:e201800282 © 2019 Imanishi et al.