Inhibition of macrophage chemotaxis by neoplastic and other rapidly proliferating cells in vitro.

Culture supernatants from rapidly proliferating cell lines inhibit macrophage chemotaxis. Of the cell lines tested, the supernatant from polyoma virus-induced tumor cells was the strongest inhibitor, although supernatants from simian virus 40-transformed 3T3, dimethylbenzanthracene-induced tumor cells, and Chinease hamster ovary fibroblasts also possessed inhibitory activity. The inhibitory substance(s) bound onto the macrophage cell surface. Although none of the culture supernatants examined were chemotactic for rat macrophages, they did possess weak attractive activity for polymorphonuclear neutrophils. This capacity of rapidly growing cells in culture to generate substances inhibitory to macrophage chemotaxis while attracting polymorphonuclear neutrophils may be relevant to the mechanism by which tumor bearing in vivo produces a cell-specific defect in chronic but not acute inflammation.