γδ T cell recognition of tumor Ig peptide

Although γδ T cells have been postulated to act as a surveillance mechanism that eliminates transformed or otherwise damaged cells, little is known about tumor recognition by γδ T cells, including the Ags that are recognized and the molecules that present them. Previously, we described human γδ CTL that recognize the autologous B cell lymphoma. Here we report that these γδ CTL lyse heterologous cells transfected with the tumor Ig λ chain gene. Furthermore, the λ 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 shock protein grp75. These findings show a specific γδ T cell response to a highly polymorphic Ag such as tumor Id and implicate heat shock protein as a molecule required for recognition.