GAMMA-DELTA T-CELL RECOGNITION OF TUMOR IG PEPTIDE

Although gamma delta T cells have been postulated to act as a surveill ance mechanism that eliminates transformed or otherwise damaged cells, little is known about tumor recognition by gamma delta T cells, inclu ding the Ags that are recognized and the molecules that present them. Previously, we described human gamma delta CTL that recognize the auto logous B cell lymphoma. Here we report that these gamma delta CTL lyse heterologous cells transfected with the tumor Ig lambda chain gene. F urthermore, the lambda chain is recognized as processed peptide in an Id-specific manner. T cell recognition does not involve classical MHC molecules, but it could be blocked by Abs directed against the heat sh ock protein grp75. These findings show a specific gamma delta T cell r esponse to a highly polymorphic Ag such as tumor Id and implicate heat shock protein as a molecule required for recognition.