Comparison of CII-specific T cell and antibody responses in arthritic vs. nonarthritic animals (day 50 postimmunization). (A) IFN-γ recall response to CII259-273 peptides, measured in sick and healthy B10.DR4.Ncf1*/* mice. Mean positive control values: arthritic mice - 17.294 ± 1.274 ng/ml; nonarthritic animals - 14.696 ± 2.266 ng/ml. (B) CII-specific T cells response in arthritic vs. nonarthritic B10.Q mice. Mean IFN-γ values for the positive control: arthritic animals - 5.199 ± 0.819 ng/ml; nonarthritic mice - 3.624 ± 0.903 ng/ml. Background INF-γ levels were subtracted from all T cell responses data. (C) and (D) Anti-CII antibody concentrations in arthritic vs. nonarthritic B10.DR4.Ncf1*/* and B10.Q mice, respectively. (E), (F) Levels of antibodies, specific to C1, U1 and J1 CII epitopes in B10.DR4.Ncf1*/* and B10.Q sick and healthy mice, respectively. All data display mean ± SE. *, P <.05; **, P <.01; ***, P <.001. CII, collagen type II; IFN, interferon.