Type ¢ñ. Mouse Soluble Interleukin 1 Receptor Antagonist Screening Model And Antagonists 139 And Immunosuppressants 335

Interleukin l(IL-1), which takes part in many physiological and pathological processes, is a kind of important cytokines. It effects by specific IL-1 receptors (IL-1R) which are present on a wide variety of different cell types. Two types of IL-1R are identified as type I receptor (IR-1RI) and type II receptor (IL-1RII). Soluble forms of IL-1R can be produced from proteolytic cleavage of the extracelluar portion of the two type receptors on cell surface. In this study, with mouse type I souble IL-1R(sIR-1RI) which was cloned and expressed in insect cell Sf₉, as targets , a kind of bioassays for screening IL-1R antagonists from natural products was set up. Using the bioassay, we got several active strains and herbs and emphatically studied Streptomyces 139. 139A was obtained from its fermentation broth. Based on the physico-chemical properties, gel chromatography and capillary electrophoresis, it was elucidated as a polysaccharide, which was not found in publication. 139A showed effective inhibition to rheumatic arthritis.