Effect of regulatory cytokines on the IL-12 response to CpG-2006. MLN cells from neonates (n = 3-5, closed bars) and adults (n = 5-7, open bars) were stimulated in vitro for 48 h with 1 μM of CpG-2006 or 1 μM of Ctl-ODN in the presence of each of various amounts of rhTGFβ1 (A), rovIL-10 (B) and rh type I IFN (E) and IL-12 secreted by MLN was assayed by ELISA (CpG-2006 - Ctl-ODN). The percentage of IL-12 secretion inhibition is shown for each dose of recombinant cytokine. MLN cells from neonates (closed circles) and adults (open squares) were cultured in vitro for 48 h, with 1 μM CpG-2006 or 1 μM of Ctl-ODN. TGFβ1 (C) and IL-10 (D) production was measured by ELISA and type I IFN activity by bioassay (F). Plot values were calculated by subtracting the values for Ctl-ODN stimulated cells from those for CpG-2006 stimulated cells. Medians are indicated for each group. * p ≤ 0.05; ** p ≤ 0.005.