Separation and comparison of two monokines with lymphocyte-activating factor activity: IL-1 beta and hybridoma growth factor (HGF). Identification of leukocyte-derived HGF as IL-6.
Supernatants of mitogen-stimulated human leukocytes contain two biologically related cytokines, IL-1 and hybridoma growth factor (HGF). IL-1 beta is a potent inducer of HGF in fibroblasts but has little stimulating effect on monocytes that spontaneously produce HGF. Leukocyte-derived HGF and IL-1 were separated by the use of affinity chromatography on specific antibodies and discriminating assay systems for both cytokines. They had different Mr upon gel filtration and SDS-PAGE. In contrast to IL-1 beta, HGF showed heterogeneity on a cation-exchange column. IL-1 beta and HGF were purified to homogeneity by a sequence of four and five purification steps, respectively. Leukocyte-derived HGF was characterized by analysis of its NH2-terminal amino acid sequence. This revealed complete homology with fibroblast-derived HGF, 26-kDa protein, IFN-beta 2, and B cell stimulatory factor 2, molecules which have collectively been designated as IL-6. IL-1 beta exerted an antiviral and growth-promoting effect of fibroblasts, whereas HGF/IL-6 did not. Both IL-1 and IL-6 possessed lymphocyte-activating factor activity, which could be neutralized only by an anti-serum against the corresponding cytokine.
Van Damme
J
J
Rega Institute for Medical Research, University of Leuven, Belgium.
Van Beeumen
J
J
Decock
B
B
Van Snick
J
J
De Ley
M
M
Billiau
A
A
D000595:Amino Acid Sequence; D000998:Antiviral Agents / Q000502:physiology; D001688:Biological Products / Q000096:biosynthesis / Q000302:isolation & purification* / Q000502:physiology; D002478:Cells, Cultured; D002846:Chromatography, Affinity; D016207:Cytokines; D005346:Fibroblast Growth Factors / Q000502:physiology; D006801:Humans; D006825:Hybridomas / Q000378:metabolism; D007375:Interleukin-1 / Q000302:isolation & purification* / Q000502:physiology; D015850:Interleukin-6; D007378:Interleukins / Q000302:isolation & purification* / Q000502:physiology; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008969:Molecular Sequence Data; D015846:Monokines
D000998:Antiviral Agents; D001688:Biological Products; D016207:Cytokines; D007375:Interleukin-1; D015850:Interleukin-6; D007378:Interleukins; D015846:Monokines; D005346:Fibroblast Growth Factors