Abstract:

Abstract:Objective To construct an interleukin-2 (IL-2) expression plasmid containing RU486 inducible system and study the regulatory effect of RU486 system on IL-2 gene expression.Methods The plasmid pRS17 containing an RU486 inducible system and plasmid pUC57-IL-2 coding mouse IL-2 gene were digested by restriction enzyme Cla Ⅰ,pRS-IL-2 was constructed by inserting IL-2 gene into pRS17.PCR and restriction enzymes were used to identify the recombinant plasmid.SMMC 7721 cells were treated with RU486 at different concentrations following transfection with recombinant plasmid.The recombinant plasmid was administered into the mice by hydrodynamic injection followed by intraperitoneal injection of RU486.The expressions of IL-2 gene in supernatant and serum were measured by using ELISA.Results By the restriction enzyme digestion and PCR analysis,the recombinant plasmid pRS-IL-2 showed the expected bands.The highest level of IL-2 was detected in the supernatant of cells treated with 10-8 mol?L-1 of RU486,which was 1.95-fold higher than that of the cells without RU486 （P<0.001）.The  serum IL-2 level  in mice after stimulation of RU486 was 320-fold higher  than before RU486 stimulation.IL-2 was undetectable in mice without RU486 injection.Conclusion The IL-2 gene expression plasmid containing RU486 inducible system is successfully constructed.The expression of IL-2 gene is dependent on RU486 presence.

Key words: interleukin-2;RU486 inducible system;gene regulation