title: Distinction of the human basophil promoting activity from human interleukin-3.
abstract: Lectin-stimulated supernatants of human peripheral blood leukocytes (PBL) contained an activity that maintained the long-term growth of murine interleukin-3 (IL-3) dependent cell lines such as the 32 Dcl line. We compared this human IL-3 activity with the basophil promoting activity (BaPA) recently described by us. Besides lectin-stimulated PBL supernatants that contained both BaPa and IL-3, we found that BaPA was produced mainly by E rosette-positive T cells or the human Mo T cell line, while IL-3 was produced by human T hybridomas and, more interestingly, by human macrophage cell lines. Based on molecular weight (BaPA: 20-30 kilodaltons, IL-3: 15-19 kilodaltons) as well as on molecular charge (BaPA: pI = 6.1-7.5, IL-3: 4.9-6.2), we concluded that human IL-3 and BaPA are distinct factors.
mesh_terms: D001491:Basophils / Q000502:physiology*; D002455:Cell Division; D002478:Cells, Cultured; D006133:Growth Substances / Q000302:isolation & purification*; D006801:Humans; D006825:Hybridomas / Q000276:immunology; D007377:Interleukin-3; D008222:Lymphokines / Q000302:isolation & purification*; D008407:Mast Cells / Q000166:cytology; D008970:Molecular Weight; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D006133:Growth Substances; D007377:Interleukin-3; D008222:Lymphokines