Characterization of a macrophage chemokinetic factor in tumor cell culture media

Media conditioned by tumor cells were studied for the presence of factor(s) that increase the rate of random migration (chemokinesis) of Corynebacterium parvum-activated macrophages. A capillary tube assay was developed and utilized to expediently monitor the chemokinetic activity of macrophages incubated in whole and fractionated media. Media conditioned by six different syngeneic and allogeneic mouse tumor cell lines demonstrated significantly higher chemokinetic activity than unconditioned or normal fibroblast conditioned media. The chemokinetically active component of the Lewis Lung conditioned media was found to be a trypsin sensitive, heat stable, high molecular weight (300,000-480,000 dalton range) factor that had no chemotactic (directional migration) activity. Pyran-activated macrophages also responded chemokinetically to the Lewis Lung factor while oyster glycogen and thioglycolate-elicited macrophages did not. The similarity and differences between the physical properties of the chemokinetic factor, other migration stimulating factors, and tumor-associated proteins are discussed.