Chemokinetic response of activated macrophages to soluble products of neoplastic cells.

cytotoxicity can be modulated in favor of the tumor-bearing host by activation with adjuvants such as Mycobacterium bovis, Corynebacteriumparvum and pyran copolymer (4,6, 20). Recent in vitro studies with the use of time lapse cinematography have shown that during coincubation with neoplastic cells the rate of random migration of M4 that were activated by BCG or pyran is much greater (3 to 5 times) than that of normal M4 (16, 25). Normal M4 obtained from mice by peritoneal lavage migrated similarly whether tumor cells were present or absent (25). However, when activated M4 were coincubated with carcinoma cells, their movement varied as a function of whether they were in physical contact with a target tumor cell. When not in contact with a tumor cell, their rate of movement tripled. This suggested a cytotropic response to a soluble product of the neoplastic cells. The experiments reported in this paper were designed to test this hypothesis. Activated and normal M4 were exposed to cell-free media from cultures of neoplastic or nonneoplastic cells. The rate of lateral movement of those M4 was then determined by time lapse cinematography.