Partial purification and characterization of a factor produced by mitogen-stimulated sheep mononuclear cells with...

Ovine peripheral blood mononuclear cells stimulated with concanavalin A released a soluble factor capable of inducing cartilage resorption and thymocyte activation in vitro, but not lysis of the murine L929 cell line. The active moiety has a molecular mass of around 15-20 kDa on gel filtration columns, and can be separated into two molecular species with isoelectric points of 6.3 and 4.6 respectively. These two species were partially purified by gel filtration, chromatofocusing, high performance liquid chromatography on hydroxylapatite and anion exchange columns, and SDS-polyacrylamide gel electrophoresis. Both partially purified species showed a major band on gels at 16 kDa. When the band from the acidic factor was excised and eluted from gels it was found to retain some cartilage-degrading and thymocyte-activating properties. The biochemical and biological characteristics of the two factors is consistent with their being members of the interleukin-1 family of cytokines.