[Lymphocyte cytotoxicity against autologous tumor cells and the effect of interferon-beta on their activities. (2) Evaluation of large granular lymphocytes (LGL)].

Large granular lymphocytes (LGL) were obtained by Percoll density gradient centrifugation of peripheral mononuclear cells from 15 patients with hematological malignancies (10 acute leukemias and 5 non-Hodgkin's lymphomas). Five-hour 51Cr-release cytotoxic assay by LGL was performed against frozen autologous tumor cells in these patients. Mean percentage cytotoxicity by LGL was 5.6%, and this was enhanced to 15.0% by the addition of IFN-beta to the culture medium. A decrease of cytotoxicity was observed when LGL was treated with anti-Leu 11b antibody plus complement, or when LGL was pretreated with the unlabelled K562 as a competitive inhibition assay. The addition of monocytes also induced a decrease of cytotoxicity, suggesting that monocytes may act as a suppressive agent in autologous tumor cell killing by LGL.