Cross-presentation of particulate exogenous antigens (phagosomes)

Dendritic cells (DCs) take up and process exogenous particulate or cell-associated antigens such as microbes or tumor cells for MHC-I cross-presentation. Particulate antigens have been reported to be more efficiently cross-presented than soluble antigens by DCs. Particulate antigens are internalized by phagosomes. There are two established models that explain the mechanism by which exogenous particulate antigens are presented through MHC I; the cytosolic pathway where internalized antigens are somehow translocated from phagosomes into cytosol for proteasomal degradation and the vacuolar pathway.

Summary from Reactome (R-HSA-1236973), read 2026-09-23.