(a) A large proportion of class II–expressing (I-A^q–expressing) cells observed on MSG cells from SS model mice compared with those on spleen and LNCs, as determined by flow cytometry. (b) MHC class II molecule induced by IFN-γ (100 U/ml) stimulation in MSG cells from non-Tx NFS/sld control mice by flow cytometry. (c) Significant proliferative responses of purified CD4⁺ T cells (2 × 10⁵) from model mice with IFN-γ–stimulated MSG cells (5 × 10⁵ and 1 × 10⁶, *P < 0.01, Student’s t test), but not from those with nonstimulated MSG cells. (d) Autoantigen-stimulated (JS-1–stimulated) proliferative T cell response of LNCs using MSG cells from SS model mice was significantly inhibited by the incubation with Clik60, but not the incubation with Clik148 and CA074 (*P < 0.01, Student’s t test). Data are expressed as stimulation indices ± SEM. Three experiments from each group were performed.