Apoptotic cells overexpress vinculin and induce vinculin-specific cytotoxic T-cell cross-priming.
Propato A., Cutrona G., Francavilla V., Ulivi M., Schiaffella E., Landt O., Dunbar R., Cerundolo V., Ferrarini M., Barnaba V.
Here we show that apoptotic cells overexpress vinculin and are ingested by dendritic cells, which subsequently cross-prime vinculin-specific cytotoxic T lymphocytes (CTLs). Successful cross-priming requires that the apoptotic cells provide maturation signals to dendritic cells through CD40-CD40 ligand (CD40L) interactions. If apoptotic cells are CD40L-, the help of a third T cell is needed for priming, indicating a regulatory role for apoptotic cells in determining priming or tolerance. Vinculin-specific CTL priming is also related to apoptosis in vivo, given that in HIV-seropositive individuals, the frequency of specific CTLs depends on the proportion of peripheral CD40L+ apoptotic cells.