title: Purification and characterization of a unique human interleukin 1 from the tumor cell line U937.
abstract: Interleukin 1 (IL 1) produced by a human tumor cell line was purified to homogeneity by a three-step chromatographic method and was tested in various assays for multiple biologic properties. The purified IL 1 stimulated the proliferative response of the D10.G4.1 cell line, a mouse IL 1 indicator T cell; caused the release of prostaglandin E2 and prostacyclin from cultured human foreskin fibroblasts and from primary human umbilical vein endothelial cells; and elicited characteristic endogenous pyrogen fever in rabbits. To stimulate IL 1 production, the histiocytic lymphoma cell line U937 was incubated with the exotoxin from toxic shock strains of Staphylococcus aureus. Supernatants from stimulated U937 cells were concentrated, and were applied to a reverse-phase HPLC column. IL 1 activity was eluted from the column at high acetonitrile concentration. Subsequent chromatography over hydroxyapatite yielded a single IL 1 species with a pI of 5.5. IL 1 was then purified to homogeneity by gel exclusion HPLC migrating as a 14 kDa species. The molecular size was confirmed by SDS-PAGE and was visualized as a single molecule by silver staining; biologic activity was recovered from the same region of the gel. Limited N-terminal sequence analysis suggested some homology to the pI 7 form of the human blood monocyte IL 1. The pI 5.5 IL 1 produced by U937 cells was only partially neutralized with anti-human monocyte IL 1 antibody, suggesting that U937-derived IL 1 is structurally related to one of the molecularly cloned IL 1 species. IL 1 from stimulated U937 cells possesses the functional characteristics of monocyte IL 1 but may represent a structurally unique IL 1 species, as determined by sequence analysis, size, and antibody reactivity.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D004727:Endothelium / Q000378:metabolism; D005334:Fever / Q000209:etiology; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D007375:Interleukin-1 / Q000096:biosynthesis / Q000302:isolation & purification* / Q000502:physiology; D007951:Leukemia, Myeloid / Q000378:metabolism*; D009000:Monocytes / Q000378:metabolism*; D011453:Prostaglandins / Q000096:biosynthesis; D014176:Protein Biosynthesis; D011506:Proteins / Q000302:isolation & purification / Q000502:physiology; D011817:Rabbits
chemical_list: D007375:Interleukin-1; D011453:Prostaglandins; D011506:Proteins; C008270:leukocyte endogenous mediator