Fig. 4.

Effect of in vivo anti-CTLA-4 MoAb and IL-12 administration on serum antibody production in orally tolerized mice. Mice were treated i. p. with either rat IgG (75 µ g /mouse) (a,e,i), anti-CTLA-4 MoAb (75 µg/mouse) (b,f,j), IL-12 (1 µg/mouse) (c,g,k) or anti-CTLA-4 and IL-12 (d,h,l) on days 0, + 1 and + 2 and fed OVA (1 mg/mouse) on days 0, + 1 and + 2. Ten days after feeding, mice were injected with 10 µg of OVA/IFA in the footpad and tail base and bled 10 days later. Sera were stored at −70°C. Sera from individual mice (3–4 mice/group) were measured for total Ig (a–d), IgG1 (e–h) or IgG2a (I–l) using ELISA (see Materials and Methods). Asterisks indicate Student's t-test values that differ significantly (P ≤ 0·05) from the corresponding value for the water-fed control. (a, e,i) B, Rat IgG/H₂O; J, rat IgG/OVA. (b, f, j) B, Anti-CTLA-4/H₂O; J, anti-CTLA-4/OVA. (c, g, k) B, IL-12/H₂O; J, IL-12/OVA. (d, h, l) B, IL-12/anti-CTLA-4/H₂O; J, IL-12/anti-CTLA-4/OVA.