Localization of a macrophage chemokinetic factor on neoplastic cells

A rabbit antiserum was produced against a high-molecular-weight fraction (360,000) of murine Lewis lung carcinoma (LLC)-conditioned media. This fraction contained a factor that increased the rate of random migration (chemokinesis) of activated macrophages (M phi) in male C57BL/6J mice. The specificity of the antiserum was demonstrated by the ability of the antiserum to absorb the chemokinetic activity from tumor-conditioned media. Immunofluorescence studies demonstrated cell surface localization of antigenetically similar material on the LLC, Ehrlich ascites cells, MCA9/14 and MCA64/8 mouse fibrosarcomas, and MBT-2 mouse bladder carcinoma. The antiserum further indicated the presence of the chemokinetic factor (CKF) on the surface of peritoneal M phi previously exposed to tumor media. The CKF was observed on approximately 90% of the Corynebacterium parvum-activated M phi and of the M phi activated by maleic anhydride-divinyl ether copolymer (fraction 2), on 10% of the oyster glycogen-elicited M phi, and on 0% of the unstimulated M phi. these data support the concept that the CKF is a common surface marker of neoplastic cells and that it is bound by activated tumoricidal M phi.