Proteasomal degradation within endocytic organelles mediates antigen cross-presentation.

ABSTRACT: During MHC-I-restricted antigen processing, peptides generated by cytosolic proteasomes are translocated by the transporter associated with antigen processing (TAP) into the endoplasmic reticulum, where they bind to newly synthesized MHC-I molecules. Dendritic cells and other cell types can also generate MHC-I complexes with peptides derived from internalized proteins, a process called cross-presentation. Here, we show that active proteasomes within cross-presenting cell phagosomes can generate these peptides. Active proteasomes are detectable within endocytic compartments in mouse bone marrow-derived dendritic cells. In TAP-deficient mouse dendritic cells, cross-presentation is enhanced by the introduction of human β₂ -microglobulin, which increases surface expression of MHC-I

SUBMITTER: Sengupta D 

PROVIDER: S-EPMC6694219 | biostudies-literature | 2019 Aug

REPOSITORIES: biostudies-literature