Susceptibility of Friend Erythroleukemia Cells to Natural Cytotoxicity after In Vitro Treatment with Dimethyl Sulfoxide

Abstract

Growth of a continuous cell line of Friend erythroleukemia cells (FLC) in medium containing 2% dimethyl sulfoxide (DMSO) resulted in a marked increase in susceptibility to natural cell-mediated cytotoxicity by spleen cells from unimmunized mice. The transition of FLC to sensitive targets was not observed until 2 days after culture initiation in DMSO. Cytolytic reactivity was not restricted by products of the major histocompatability complex since both syngeneic and allogeneic effector cells responded similarly. Preincubation of effector cells in mouse fibroblast interferon augmented the cytotoxic reactivity in a dose-dependent manner against DMSO-grown FLC but had no influence on the ability of spleen cells to lyse untreated FLC. The adherence properties of effector cells on nylon wool, glass wool, and plastic surfaces were consistent with those of macrophages. Amphotericin Bseemed also to be required for the transition of FLC to sensitive targets. The increased susceptibility of the DMSO-treated leukemia cells to natural cytotoxicity may be due to enhanced recognition by splenic macrophages.