FcγRIIa ligation increases sensitivity to TLR ligands and relies on IgG1 and IgG2. (A) DCs were stimulated with plate-bound IgG and different concentrations of LPS or PGN. After 24 hours, cytokine levels in the supernatant were determined by ELISA. Data shown are from 1 representative experiment of at least 5 experiments with different donors. (B) DCs were stimulated with LPS in combination with either plate-bound total IgG, IgG1, IgG2, or IgG3. After 24 hours, cytokine levels in the supernatant were determined by ELISA. Data shown are from 1 representative experiment of at least 3 experiments with different donors. Error bars indicate SEM; *P < .05, **P < .01; ns indicates not significant; paired t test.