CD4 and arthritic joint disease: As previously shown, T2-MZP Bregs suppressed arthritis and reduced the frequency and absolute number of IFN-γ+ and IL-17+CD4+ T cells in WT mice; however, WT T2-MZP Bregs were unable to convey the same suppressive effect in iNKT cell-deficient mice (Fig. 6a, b).