Fig. 3.

Ex vivo stimulation of human B cells increased IgG secretion. (A) IgG secretion in the supernatants of B cell cultures following activation with different stimuli showed IL-17+BAFF+CpG, and to a lesser extent CpG alone, yielded significantly higher IgG titres on day 15 (n = 2 independent experiments from two human healthy volunteers; 10 wells per experiment, of 200 B cells per well). (B) Increased IgG secretion in the presence of IL-17+BAFF+CpG compared to CpG at different plating densities of B cells (300, 200, 150 or 50 cells per well; representative experiment). (C) Stimulation with IL-17+BAFF+CpG (50 B cells per well) increased IgG secretion in CD19⁺CD22⁺CD27⁺IgD^- class-switched memory B cells but not in CD19⁺CD22⁺CD27^-IgD⁺ mature naive B cells.