Phagocytosis of murine lymphoma cells by macrophages. I. Factors affecting in vitro phagocytosis.

Factors affecting phagocytosis of a DBA/2 lymphoma, L5178Y, were investigated. Peritoneal macrophages from mice injected with thioglycollate medium were found to take up more lymphoma cells than those from normal mice. The number of cells phagocytosed by normal macrophages was found to be related to the concentration of antiserum employed and the number of lymphoma cells added to each macrophage slip culture. Treatment of macrophages or lymphoma cells with either trypsin or neuraminidase prior to the opsonic test greatly increased the number of cells ingested and also the number of macrophages containing ingested lymphoma cells. The relevance of the results from this opsonic test system to findings is discussed.