title: Human monocytes generate basophil histamine-releasing activities.
abstract: Human peripheral blood monocytes generated activities during 24-h culture that were capable of triggering histamine release from 17 of 18 human basophil donors. Monocytes and their in vitro transformed macrophages continued to elaborate these basophil histamine-releasing activities for at least 3 wk in culture. In the 18 basophil donors tested, maximum histamine release induced by monocyte supernatants was 33.8 +/- 5.9% (mean +/- SEM) of total basophil histamine content; optimum anti-IgE-induced release was 38.8 +/- 6.2%. Basophil histamine release in response to monocyte activities was optimal at 37 degrees C and at calcium concentrations of 2 to 5 mM. Release was greater than 90% complete 1 min after challenge and was inhibited by anti-allergic drugs. The mechanism of release appeared to be independent of IgE binding. Gel filtration of supernatants derived from both day 1 (monocyte stage) and day 14 (macrophage stage) cultures demonstrated activity peaks with approximate m.w. of 12,000 and 30,000. In contrast to the marked responsiveness of basophils, only 2 of 10 human lung mast cell preparations responded; release in those preparations was low: 3% and 13% histamine release, respectively. Thus, monocytes produce potent histamine-releasing activities with differential actions on basophils and mast cells.
mesh_terms: D001491:Basophils / Q000276:immunology* / Q000378:metabolism; D002118:Calcium / Q000494:pharmacology; D003888:Desensitization, Immunologic; D004306:Dose-Response Relationship, Immunologic; D006636:Histamine Release / Q000187:drug effects; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology; D007700:Kinetics; D008168:Lung / Q000166:cytology / Q000276:immunology; D009637:Masoprocol / Q000494:pharmacology; D009000:Monocytes / Q000276:immunology* / Q000378:metabolism; D013696:Temperature
chemical_list: D007166:Immunosuppressive Agents; D009637:Masoprocol; D002118:Calcium