Abstract
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 CD8 alpha(+) and CD8 alpha(-) 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 CD8 alpha(+) and CD8 alpha(-) as well as BMDCs. CD8 alpha(-) DCs were more efficient at inducing T cell proliferation when they acquired Ag via cross-presentation, the opposite was observed for BMDCs and splenic CD8 alpha(-) DCs. We conclude from these observations that the relative efficiency of MHC transfer vs cross-presentation differs markedly between different DC subsets.
| Original language | English |
|---|---|
| Pages (from-to) | 3212 - 3220 |
| Number of pages | 9 |
| Journal | Journal of Immunology |
| Volume | 181 |
| Issue number | 5 |
| Publication status | Published - 2008 |