Apoptotic cells overexpress vinculin and induce vinculin-specific cytotoxic T-cell cross-priming

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 liga nd (CD40L) interactions. If apoptotic cells are CD40L; the help of a third T cell is needed for priming, indicating a regulatory role for apoptotic ce lls in determining priming or tolerance. Vinculin-specific CTL priming is a lso related to apoptosis in vivo, given that in HIV-seropositive individual s, the frequency of specific CTLs depends on the proportion of peripheral C D40L(+) apoptotic cells.