cGAMP MPs induce STING-dependent IL-10 and IL-27 production in APCs in vitro. (A and B) BMDCs from WT, Tmem173gt/gt, or Ifnar−/− mice were primed with LPS for 3 h prior to the addition of increasing concentrations of MP-encapsulated cGAMP (0.2–5 μg/ml), equivalent soluble cGAMP, or blank MP controls. IL-10 and IL-27 were measured in supernatants. (C and D) BMDMs from WT, Tmem173gt/gt, or Ifnar−/− mice were conditioned as described above and assayed for IL-10 and IL-27. All supernatants were collected after 24 h and assayed by ELISA. Combined data of two experiments, six biological replicates (n = 6). Student t test was used for cGAMP MP concentrations and their equivalent soluble dose. Data are presented as mean ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.