Peptide binding to surface class II molecules is the major pathway of formation of immunogenic class II-peptide complexes for viable antigen presenting cells.

Although studies on fixed APCs have demonstrated that peptide can bind to cell surface class II molecules, the mechanisms by which peptide-class II complexes are formed in viable cells is largely unexplored. To explore the possibility that peptide loading of class II molecules was occurring after endocytosis of peptides as well as by surface binding, we… (More)