Sensitivity of glioma and fetal brain cell lines to natural killer cytolysis in a monolayer assay.

We have developed an in vitro assay for Natural Killer (NK) cell cytolysis of and binding to substrate attached human glioma and fetal brain cells. The monolayer cells were labeled with [51Cr] and the effectors were directly sedimented onto these substrate attached target cells. Using this method we screened several glioma and fetal brain cell lines. The results indicate that the majority of gliomas are NK resistant, however two of the tested lines (U251MG and BN3) were relatively sensitive as were the fetal brain cell lines (CHI and CHII). We conclude that this monolayer assay for NK cytotoxicity and binding of glioma targets is a reproducible and valid method for assessing NK sensitivity, and should have applications in the study of other cultured solid tumors and substrate attached cells.