Selective transport of internalized antigens to the cytosol for MHC class I presentation in dendritic cells.
In order for cytotoxic T cells to initiate immune responses, peptides derived from internalized antigens must be presented to the cytotoxic T cells on major histocompatibility complex (MHC) class I molecules. Here we show that dendritic cells, the only antigen-presenting cells that initiate immune responses efficiently, have developed a unique membrane transport pathway linking the lumen of endocytic compartments and the cytosol. Endosome-to-cytosol transport is restricted to dendritic cells, specific to internalized antigens and selective for the size of the transported molecules. Thus, in dendritic cells, internalized antigens gain access to the cytosolic antigen-processing machinery and to the conventional MHC class I antigen-presentation pathway.
Rodriguez
A
A
Institut National de la Santé et de la Recherche Médicale U520, Institut Curie, Section de Recherche, 75005 Paris, France.
Regnault
A
A
Kleijmeer
M
M
Ricciardi-Castagnoli
P
P
Amigorena
S
S
D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D000941:Antigens / Q000276:immunology / Q000378:metabolism*; D001692:Biological Transport; D002478:Cells, Cultured; D003600:Cytosol / Q000276:immunology; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology*; D004705:Endocytosis / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D008264:Macrophages / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D010047:Ovalbumin / Q000276:immunology
D000941:Antigens; D015395:Histocompatibility Antigens Class I; D010047:Ovalbumin