NOVEL TUMOR-ASSOCIATED ACCESSORY MOLECULES INVOLVED IN THE GAMMA DELTA CYTOTOXIC T-LYMPHOCYTE BURKITTS-LYMPHOMA INTERACTION/

Background. Tumor specific cytotoxic T lymphocytes (CTL) recognize ant igen via the T-cell receptor (TCR). In addition, recognition requires accessory molecules involved in adhesion and signal transduction. The authors previously have characterized an autologous, Burkitt's lymphom a specific CTL line that uses the gamma-delta TCR to recognize antigen in a nonclassical context. The current study was undertaken to identi fy novel accessory molecules involved in this unusual TCR-tumor cell i nteraction. Methods. A panel of monoclonal antibodies was generated ag ainst a Burkitt's lymphoma cell line and was screened for inhibition o f autologous, tumor specific, cytolysis by a gamma-delta CTL line. Pro teins identified by these monoclonal antibodies were further character ized by fluorescent-activated cell sorter analysis, Western blot and i mmunoprecipitation. Results. Three known (CD5, CD43, and CD11a/CD18) a nd three novel (BAM-1, BAM-2, and BAM-3) cell surface molecules involv ed in the gamma-delta CTL-Burkitt's lymphoma interaction were identifi ed and characterized. Conclusions. This study identifies and provides a preliminary characterization of three novel Burkitt's lymphoma-assoc iated molecules involved in the gamma-delta CTL-tumor cell interaction and demonstrates that CD5, CD43, and CD11a/CD18 are involved in this interaction. It is likely that other unidentified accessory molecules are also involved in this and other effector cell-tumor interactions. Identification of such molecules may be useful in the design of new im munotherapeutic approaches.