siRNA knockdown of MK2 suppresses TNF-α production but has only a modest effect on IL-1β production. T-shNT and T-shFC cells were double-transfected with a pool of siRNAs directed against MAPKAPK-2 (siMK2) or a pool of nontargeted siRNAs using Nucleofector II and cultured for 72 hours. (A) Whole cell extracts were then prepared and subjected to western blot analysis of MK2. Band densitometry was performed using ImageJ software. (B-C) After the 72-hour culture period, cells were plated at a concentration of 106 per mL and then stimulated with R848 (30 μM) for 24 hours. Secreted IL-1β (B) and TNF-α (C) were measured in the conditioned media by ELISA. Two experiments were carried out. One representative experiment with 3 biological replicates for each condition is shown. P values were calculated using a paired Student t test.