After self peptide (purple) is processed in CD103+ dendritic cells (DCs, green), antigen-MHC class II complex is presented to antigen-specific CD4+ T cells (red). Adjuvant stimulates toll-like receptors (TLR) and enables co-stimulation (not shown). Antigen presentation by CD103+ tolerogenic DCs likely induces the clonal expansion and the differentiation of antigen-specific CD4+ T cells to Treg cells, resulting in the suppression of inflammation and the reduction of atherosclerosis. Memory Tregs may form, persist and recirculate, resulting in durable atheroprotection.