Inducible IL-12 gene expression mediated by naked DNA containing an RU486 regulatory system / 中华微生物学和免疫学杂志

ABSTRACT

Objective To evaluate the inducibility of target gene expression induced by plasmid DNA carrying a RU486 regulatory system. Methods Plasmid pRS-LacZ encoding LacZ gene and plasmid pRS22 encoding murine interleukin-12(IL-12)gene were used to bansfect cells in vitro or be rapidly injected into the vein of mice. Then LacZ expression was assayed in cultured cells and tissues by X-gal staining.The IL-12 level was tested in the supernatants of cultured cells and in the serum with ELISA. ResultsIn the presence of RU486.30％ of the liver derived hepatic HepG2 cells were dyed blue while less than 1％of the HepG2 cells were blue colored in the absence of RU486. Less than 0.5％ of other non-hepatic cells were in blue with or without RU486. After transfection, the IL-12 level in the supernatants of HepG2 cells increased with increasing concentrations of RU486 treatment. After intravenous injection of plasmid pRS-LacZ,blue colored cells were observed only in liver tissue while induced by RU486. After intravenous injection of plasmid pRS22,the IL-12 expression level in serum was related with the dosage of RU486 or/and plasmid DNA. Conclusion Plasmid DNA containing RU486 regulatory system could open or close IL-12 gene expression by the addition or deletion of RU486. And the IL-12 expression level in serum could be regulated by altering the dose of plasmid DNA or/and RU486.