Figure 3.

Schematic visualization of our hypothesis. In cancer or upon infection, professional antigen-presenting cells take up antigens released by dying cells, degrade them in the endosome-lysosome compartments, and present their longer peptides as either HLA-II or HLA-I peptides in a proteasome-independent manner. In addition, shorter HLA-I peptides are presented via the conventional proteasome-dependent class I pathway. In case cells are directly infected with intracellular pathogens or at steady state conditions, autophagy may similarly lead to the presentation of longer peptides, from the pathogens or from the self proteome, including as HLA-I.