FIG 4.

R232H variant of STING responds normally to S. pneumoniae infection or stimulation with pneumococcal DNA. PBMCs from healthy volunteers were isolated by density gradient centrifugation. Seven days after isolation, cells were challenged for 6 h with S. pneumoniae at a multiplicity of infection of 2.5 or stimulated for the same period with 1 μg/ml pneumococcal DNA. RNA was isolated, and the expression of IFNB (A), IL1B (B), TNFA (C), and IL-6 (D) was determined by qRT-PCR. Data are shown as the RQ of specified mRNAs. Data represent the means ± SD from 3 independent experiments carried out in triplicates. Differences were assessed with the Mann-Whitney U test.