Endogenous HAQ STING is strongly impaired in mounting a type I IFN and proinflammatory cytokine responses against <i>Legionella</i> infection or stimulation with DNA or CDNs.

<p>(A-D) PBMCs from healthy volunteers (N = 4 for WT and N = 4 for HAQ) were isolated by density gradient centrifugation. 7 d after isolation cells were infected for 6 h with <i>L</i>. <i>pneumophila</i> at MOIs 10 and 50 or stimulated for the same period with 1 and 5 ug/ml 2´-3´cGAMP or either bacterial or synthetic DNA at a concentration of 0.2 or 1 ug/ml. RNA was isolated and the expression of <i>IFNB</i> (A), <i>IL1B</i> (B), <i>IL6</i> (C) and <i>TNFA</i> (D) was determined by qRT-PCR. Data are shown as the RQ of specified mRNAs. Data represent the mean ± SEM of 4 independent experiments carried out in triplicates. Differences were assessed with the Mann-Whitney U Test. Comparisons with a p < 0.05 were considered significant.</p>