Figure 2.

CD4 T cell immunodominance is shaped by two distinct and selective stages during priming. In the first stage of selection of CD4 T cells, intracellular DM “editing” promotes immunodominance of high stability class II: peptide complexes by dictating the initial epitope density on priming DC, which allows differential initial recruitment of CD4 T cells. In the second stage, or after multi-peptide immunization, regulatory events induced by dominant CD4 T cells (indicated in blue), including production of IFN-γ, and resulting IDO and Treg induction and production of kynurenines further refine the CD4 repertoire by inhibiting full expansion of CD4 T cells specific for lower stability complexes, indicated in yellow and green.