INDUCTION OF MACROPHAGE GROWTH BY HEAT-STABLE FACTOR IN TUMOROUS ASCITIC FLUID

  • 1 January 1984
    • journal article
    • research article
    • Vol. 54  (3) , 117-124
Abstract
Peritoneal macrophages from mice synthesized DNA and proliferated in vitro in the presence of cell-free tumorous ascites. The growth stimulating activity of ascitic fluid was stable on heat treatment (100.degree. C, 30 min). The macrophage growth stimulating activity of mouse neoplastic fibroblast L cell-conditioned medium was inactivated by heat treatment. The growth factor(s) in heat-treated ascitic fluid was stable at pH 2 and 10 and on treatment with 2-mercaptoethanol or urea. Treatments, with enzymes such as trypsin, pronase, phospholipase and neuraminidase and with sodium periodate oxidation partially inactivated the macrophage growth stimulating activity of the heat-stable factor(s). The adherent cultured cells that proliferated in heat-treated ascitic fluid were macrophages, as indicated by their nonspecific esterase staining, pinocytosis and phagocytosis. These macrophages showed cytolytic activity against a murine tumor in the presence of wheat germ agglutinin, but not antitumor antibody. Tumorous ascitis fluid contains a heat-stable macrophage growth factor(s) distinct from the colony stimulating factor and the proliferated macrophages killed tumor cells in cooperation with a lectin.