Human gamma delta T cells recognize heat shock protein-60 on oral tumor cells

In the present investigations, gamma delta T cells were isolated from the p eripheral blood of oral cancer patients and analyzed for their immunophenot ype and cytotoxic potential. Flowcytometric analysis revealed a dominant po pulation expressing V gamma 9 and V delta 2 T-cell receptors, In a 4-hr Cr- 51-release assay, activated gamma delta T cells showed specific cytotoxicit y against Daudi Burkitt's lymphoma cells and fresh oral tumor cells. Cold t arget competition assays demonstrated that gamma delta T cells recognize a common ligand on Daudi and oral tumor cells. Expression of heat shock prote in 60 (hsp60) molecules was detected on the surface of Daudi as well as ora l tumor cells by now cytometry and immunoprecipitation of surface biotinyla ted cells by anti-hsp60 monoclonal antibody (MAb). Such MAbs brought about a significant inhibition of cytotoxicity of gamma delta T cells against Dau di and oral tumor cells. The results suggest that gamma delta T cells isola ted from the peripheral blood of oral cancer patients have the ability to l yse oral tumor cells. The lysis of oral tumor cells occurs via recognition of hsp60 on the surface of oral tumor cells. Int. J, Cancer 80:709-714, 199 9, (C) 1999 Wiley-Liss, Inc.