Direct antigen presentation and gap junction mediated cross-presentation during apoptosis.
MHC class I molecules present peptides from endogenous proteins. Ags can also be presented when derived from extracellular sources in the form of apoptotic bodies. Cross-presentation of such Ags by dendritic cells is required for proper CTL responses. The fate of Ags in cells initiated for apoptosis is unclear as is the mechanism of apoptosis-derived Ag transfer into dendritic cells. Here we show that novel Ags can be generated by caspases and be presented by MHC class I molecules of apoptotic cells. Since gap junctions function until apoptotic cells remodel to form apoptotic bodies, transfer and cross-presentation of apoptotic peptides by neighboring and dendritic cells occurs. We thus define a novel phase in classical Ag presentation and cross-presentation by MHC class I molecules: presentation of Ags created by caspase activities in cells in apoptosis.
Pang
Baoxu
B
Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
Neijssen
Joost
J
Qiao
Xiaohang
X
Janssen
Lennert
L
Janssen
Hans
H
Lippuner
Christoph
C
Neefjes
Jacques
J
D017951:Antigen Presentation / Q000276:immunology*; D017209:Apoptosis / Q000276:immunology*; D053453:Caspase 9 / Q000378:metabolism; D020169:Caspases / Q000378:metabolism; D002460:Cell Line; D018920:Coculture Techniques; D018031:Connexin 43; D045142:Cross-Priming; D003713:Dendritic Cells / Q000276:immunology; D017629:Gap Junctions / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D006801:Humans
D018031:Connexin 43; D015395:Histocompatibility Antigens Class I; D053453:Caspase 9; D020169:Caspases