Wikipedia says that: "The antigens presented by MHC class II are derived from extracellular proteins (not cytosolic as in MHC class I)."
So does this mean that MHC class I cannot be used for peptides derived from phagocytosis by non-professional APCs? (i.e. peptides that of extracellular origin?).
For example, when non-professional APCs that can undergo phagocytosis (Eosinophil, neutrophil, dendritic cell) engulf bacteria, will they present their antigens using MHC I although the peptides are of extracellular origin? or will they not present any MHC at all? thanks!