Figure 2.
Employment of Ii for stable presentation of a desired antigenic peptide by DCs. The translated Ii-antigen peptide enters the ER and binds to an MHC class II molecule, with the antigenic peptide occupying the peptide-binding groove of the MHC molecule. In the lysosomal compartments, the Ii chain is degraded, leaving the desired antigenic peptide in the peptide-binding groove of the MHC class II molecule and allowing for the stable presentation of the antigenic peptide on the cell surface.