Fig. 1. Processing and presentation of HLA-bound self- and foreign-peptides.
A) Peptides are generated through proteolysis in the proteosome, transported to the endoplasmic reticulum by transporters associated with antigen processing (TAP), associated with HLA molecules therein and then exported and cell surface displayed. B) Artistic rendition of 50,000 to 100,000 peptide-MHC complex (pMHC) molecules on a cell surface (blue/purple) with a single tumor antigen (yellow) among the MHC-bound peptidome, emphasizing the daunting challenge of TCR-based recognition. This figure was rendered by Steve Moskowitz of Advanced Medical Graphics, Boston, MA.