a Department of Internal Medicine (P.C., M.G., S.B., G.F., F.I., F.P.), University of Genoa, Genoa, Italy
b Department of Experimental Medicine (A.M.), University of Genoa, Genoa, Italy
Abstract:
In the present study, we report that allogeneic soluble HLA class I (sHLA-I) molecules isolated from serum induce apoptosis on EBV-specific CD8+ Fas+ cytotoxic T lymphocytes (CTL). CTL apoptosis is induced by the binding of sHLA-I molecules to CD8 and its extent depends on the time of incubation with sHLA-I molecules. Apoptosis is triggered by the interaction of Fas+ CTL with soluble Fas-ligand, which is released following the binding of sHLA-I antigens to CD8 molecules. These results suggest that sHLA-I molecules may regulate immune responses by inducing apoptosis in virus-specific CTL.