Localization of a Macrophage Chemokinetic Factor on Neoplastic Cells 1,2,3

ABSTRACT-A rabbit antiserum was produced against a high-molecular-weight fraction (360,000) of murine Lewis lung carci-noma (LLC)-conditioned media. This fraction contained a factor that increased the rate of random migration (chemokinesis) of activated macrophages (M~) in male C57BLl6J mice. The specificity of the antiserum was demonstrated by the ability of the antiserum to absorb the chemokinetic activity from tumor-con-ditioned media. Immunofluorescence studies demonstrated cell surface localization of anti genetically similar material on the LLC, Ehrlich ascites cells, MCAgl14 and MCA64f8 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 ~ previously exposed to tumor media. The CKF was observed on approximately 90 % of the Corynebacterium parvum-activated Mcp and of the Mcp activated by maleic an