Endogenous R232H STING is partly deficient in sensing bacterial CDN but responds normally to Legionella infection or stimulation with DNA.

(A-D) PBMCs from healthy volunteers (N = 3 for WT and N = 3 for R232H) were isolated by density gradient centrifugation. 7 d after isolation cells were infected for 6 h with L. pneumophila at MOI 10 or stimulated for the same period with 1 ug/ml 2´-3´cGAMP, Rp-c-diAMPSS, cGMP or either bacterial DNA at a concentration of 1 ug/ml. RNA was isolated and the expression of IFNB (A), IL1B (B), and IL6 (C) and TNFA (D) was determined by qRT-PCR. Data are shown as the RQ of specified mRNAs. Data represent the mean ± SEM of 3 independent experiments carried out in triplicates. Differences were assessed with the Mann-Whitney U Test. Comparisons with a p < 0.05 were considered significant.