title: Effect of various immunoregulatory substances on the growth inhibitory activity (GIA) of human monocytes against lymphoblastoid cell lines.
abstract: Human peripheral blood monocytes, isolated by adherence to plastic surfaces or elutriation by size, were tested for growth inhibitory activity (GIA) against human and mouse lymphoblastoid cell lines. Cells isolated by either method inhibited incorporation of 3H-thymidine of both target cells, but did not affect phytohemagglutinin-induced blasts. GIA was appreciably higher when the assays were performed in medium with human serum rather than fetal calf serum. Interferon significantly augmented GIA at a 10:1 effector:target (E/T) radio in a 24 hr assay, and at an E/T ratio of 30:1 in a 48 hr assay. Preincubation with phorbol myristate acetate (PMA) caused a threefold or greater increase in GIA by monocytes. Prostaglandins or indomethacin, as well as corticosteroids, did not influence GIA. Superoxide dismutase and catalase were not found to affect GIA when added to the assay. cytostatic activity by human monocytes is apparently subject to positive regulation, but not to suppression by prostaglandins. The mechanism responsible for GIA remains undetermined, but appears to be independent of superoxide radical generation.
mesh_terms: D002460:Cell Line; D003470:Culture Media / Q000494:pharmacology; D003601:Cytotoxicity Tests, Immunologic; D006131:Growth Inhibitors / Q000096:biosynthesis*; D006801:Humans; D007372:Interferons / Q000494:pharmacology; D009000:Monocytes / Q000276:immunology* / Q000378:metabolism; D009374:Neoplasms, Experimental / Q000473:pathology; D010703:Phorbol Esters / Q000494:pharmacology; D011453:Prostaglandins / Q000494:pharmacology; D013045:Species Specificity; D013482:Superoxide Dismutase / Q000494:pharmacology
chemical_list: D003470:Culture Media; D006131:Growth Inhibitors; D010703:Phorbol Esters; D011453:Prostaglandins; D007372:Interferons; D013482:Superoxide Dismutase