Figure 6
Effect of neutralization of IL-17 in the presence or absence of anti-IFN-γ and/or anti-IL-4 during the initiation phase of arthritis. (a) Neutralizing antibody to IFN-γ (clone R46A2, 100 μg/mouse/day), and/or neutralizing antibody to IL-4 (clone 11B11, 100 μg/mouse/day), and neutralizing antibody to IL-17 (clone M210, 100 μg/mouse/day) was administered intraperitoneally from day 10 to 20 after immunization with collagen and complete Freund's adjuvant (CFA). Rat IgG was used as isotype control. The control group did not receive any antibody. Arthritis was assessed from day 10 by clinical scoring. n = 8 to 9/group. * P < 0.05, ** P < 0.01 *** P < 0.001. (b) Correlation analysis of serum IL-17 to clinical scores of arthritis severity in the anti-IFN-γ and the anti-IFN-γ + anti-IL-4 groups. (c) Splenocytes from the different groups were cultured overnight with collagen. Following six-hour stimulation with PMA/ionomycin/BrefeldinA, cells were stained with fluorescent labeled anti-CD4, anti-IL-17, anti-IFN-γ, and anti-IL-4 antibodies and analyzed on FACS Calibur using Cell Quest software. * P < 0.05. (d) Tissue sections of arthritic hind paw from mice that received neutralizing antibodies to IFN-γ alone, IFN-γ + IL-17, IFN-γ + IL-4, IFN-γ + IL-4 + IL-17, rat IgG or no antibody were stained with hematoxylin and eosin. The sections were scored for inflammatory infiltrate, synovitis, bone damage and cartilage destruction. Data are presented as mean +/- standard deviation.