title: Immunostimulators induce granulocyte/macrophage colony-stimulating activity and block proliferation in a monocyte tumor cell line.
abstract: Monocyte tumor cell line PU5-1.8 does not normally produce colony-stimulating activity (CSA) required by granulocyte and macrophage progenitors to proliferate and mature in agar. However, CSA is induced in the culture line by as little as 10 ng/ml endotoxic lipopolysaccharide (LPS), with maximum CSA production and release to the medium between 2 and 3 days of incubation. Derived lipid A, but not alkali-treated LPS, is also active. Induction requires RNA and protein synthesis, but is not blocked by mitomycin C or Colcemid. Other inducers of CSA include Mycobacterium Bacillus Calmette-Guérin, tuberculin protein preparation purified protein derivative, zymosan, and phorbol myristate. All inducing agents are specific inhibitors of the monocyte tumor cell proliferation in vitro. Latex beads, another macrophage-activating agent, are rapidly phagocytosed by PU5-1.8 cells, but neither inhibit growth nor induce CSA.
mesh_terms: D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D003115:Colony-Stimulating Factors / Q000096:biosynthesis*; D006023:Glycoproteins / Q000096:biosynthesis*; D006098:Granulocytes / Q000187:drug effects / Q000276:immunology*; D007109:Immunity; D066298:In Vitro Techniques; D007700:Kinetics; D007962:Leukocytes / Q000276:immunology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects / Q000276:immunology*; D051379:Mice; D009000:Monocytes / Q000166:cytology* / Q000187:drug effects; D009369:Neoplasms / Q000276:immunology*
chemical_list: D003115:Colony-Stimulating Factors; D006023:Glycoproteins; D008070:Lipopolysaccharides