CD4 and rheumatoid arthritis: The induction of regulatory T cells (Treg) by peptide-based therapies have been developed for the treatment of a number of autoimmune diseases including RA,80 multiple sclerosis (MS) and Graves’ disease.81–83 In this treatment, known tolerogenic peptides bind directly to MHC II on DCs.84 These DCs then interact with CD4 T cells to induce regulatory T cells that suppress T cell activation.