Antineoplastic effects of natural killer cells sorted with flow cytometry on brain tumors.

For the purpose of FCM, we have developed a new method of sterile sorting of NK cells by negative selection using FITC-labelled monoclonal antibodies. In this method, over 95% lymphocytes with large granular lymphocytes (NK cells) were obtained by exclusion of Leu-1 and HLA-DR positive cells from human peripheral blood. From the results of cytotoxicity test of NK cells against 4 types of glioma cell lines and 6 kinds of cultured cells from surgical materials, the antineoplastic effect was recognized in 4 out of 6 surgical materials. Administration of NK cells through an Ommaya tube in 2 brain tumor patients caused no side effects. This technique is clinically applicable because 1) NK cells are easy to obtain, 2) NK cells show antineoplastic effect on brain tumors, and 3) the sensitivity can be evaluated in individual patients.