A proteasome-dependent, TAP-independent pathway for cross-presentation of phagocytosed antigen

作者：Merzougui Nawel; Kratzer Roland; Saveanu Loredana^*; van Endert Peter

来源：EMBO Reports, 2011, 12(12): 1257-1264.

DOI：10.1038/embor.2011.203

• antigen presentation
• cross-presentation
• transporters associated with antigen processing
• proteasome
• MHC class I

Major histocompatibility complex (MHC) class I cross-presentation is thought to involve two pathways, one of which depends on both the TAP transporters and the proteasome and the other on neither. We found that preincubation of TAP-deficient dendritic cells at low temperature increases the density of MHC class I at the surface and fully restores cross-presentation of phagocytosed antigen, but not of soluble antigen internalized through receptors. Restoration of cross-presentation by TAP-deficient cells requires antigen degradation by the proteasome. Thus, TAP might mainly be required for recycling cell surface class I molecules during cross-presentation of phagocytosed antigens. Furthermore, phagosomes-but not endosomes-seem to have a TAP-independent mechanism to import peptides generated by cytosolic proteasome complexes.

• 出版日期2011-12