LYMPHOKINE ACTIVATED KILLER (LAK) CELL-MEDIATED LYSIS OF MURINE GLIOMA - TRYPSINCHYMOTRYPSIN-SENSITIVE GLIOMA PROTEIN IS RESPONSIBLE FOR TUMOR-SELECTIVE RECOGNITION BY LAK CELLS

The killing of Fischer rat 9L glioma in vitro by lymphokine-activated killer (LAK) cells was studied. LAK cells generated by culturing Fischer spleen cells with recombinant interleukin 2 markedly lysed glioma cells but did not kill syngeneic normal brain tissue in a chromium release microcytotoxicity assay. Susceptibility of glioma to lysis by LAK cells was markedly diminished by pretreating the glioma cells with trypsin or chymotrypsin but was unaffected by pretreatment with neuraminidase, glycosidases, or sodium periodate. These results suggest that LAK cell killing of glioma is probably tumor-selective and that a crucial cell surface determinant on glioma cells responsible for its tumor-selective lysis by LAK is a protein sensitive to trypsin and chymotrypsin.