The relative efficiency of acquisition of MHC:peptide complexes and cross-presentation depends on dendritic cell type.
Intercellular exchange of MHC molecules has been reported between many cells, including professional and nonprofessional APCs. This phenomenon may contribute to T cell immunity to pathogens. In this study, we addressed whether the transfer of MHC class I:peptide complexes between cells plays a role in T cell responses and compare this to conventional cross-presentation. We observed that dsRNA-matured bone marrow-derived dendritic cells (BMDCs) acquired peptide:MHC complexes from other BMDCs either pulsed with OVA(257-264) peptide, soluble OVA, or infected with a recombinant adenovirus expressing OVA. In addition, BMDCs were capable of acquiring MHC:peptide complexes from epithelial cells. Spleen-derived CD8alpha(+) and CD8alpha(-) dendritic cells (DCs) also acquired MHC:peptide complexes from BMDCs pulsed with OVA(257-264) peptide. However, the efficiency of acquisition by these ex vivo derived DCs is much lower than acquisition by BMDC. In all cases, the acquired MHC:peptide complexes were functional in that they induced Ag-specific CD8(+) T cell proliferation. The efficiency of MHC transfer was compared with cross-presentation for splenic CD8alpha(+) and CD8alpha(-) as well as BMDCs. CD8alpha(+) DCs were more efficient at inducing T cell proliferation when they acquired Ag via cross-presentation, the opposite was observed for BMDCs and splenic CD8alpha(-) DCs. We conclude from these observations that the relative efficiency of MHC transfer vs cross-presentation differs markedly between different DC subsets.
Smyth
Lesley Ann
LA
Department of Nephrology and Transplantation, King's College London, School of Medicine, Guy's Hospital, London, United Kingdom.
Harker
Nicola
N
Turnbull
Wayne
W
El-Doueik
Haytham
H
Klavinskis
Linda
L
Kioussis
Dimitris
D
Lombardi
Giovanna
G
Lechler
Robert
R
D000818:Animals; D001853:Bone Marrow; D018414:CD8-Positive T-Lymphocytes / Q000502:physiology; D049109:Cell Proliferation; D045142:Cross-Priming; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology*; D004847:Epithelial Cells / Q000276:immunology; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D051379:Mice; D010047:Ovalbumin; D010446:Peptide Fragments; D010455:Peptides / Q000276:immunology*; D013154:Spleen
D015395:Histocompatibility Antigens Class I; C110366:OVA-8; D010446:Peptide Fragments; D010455:Peptides; D010047:Ovalbumin