L. pneumophila infection and stimulation with DNA or cGAMP induce weak cGAS-dependent type I IFN responses in THP-1 cells.

WT THP-1 or cGAS-/- THP-1 clones A5 and B5 were allowed differentiation prior to stimulation with either cGAMP or synthetic DNA (A) or infection with two different strains of L. pneumophila (B). IFNB expression was determined by qRT-PCR. Data represent mean ± SEM of 2 independent experiments carried out in duplicates. Analyses were performed by employing the Mann-Whitney U Test. Comparisons with a p < 0.05 were considered significant.