The establishment of the uPA inducible expression system / 中国比较医学杂志

ABSTRACT

Objective To establish uPA inducible expression system using recombinant retroviral system for the further construction of inducible uPA-SCID animal model .Methods The Inducible expression system need to construct two plasmidspLNHXO1O2-Alb-GLUC-FMN2A -rtTA and pLNHXO5O6-TRE2-uPA-IRES-ZsGreen respectively. Both plasmids were based on retroviral vector pLNHX , Albumin promoter gene ( Alb) and rtTA gene or uPA gene and ZsGreen were obtained by PCR reaction and inserted into pLNHX .The Gaussia enzyme fluorescent element ( GLUC) was used to monitor rtTA expression in pLNHXO1O2-Alb-GLUC-FMN2A-rtTA, and the ZsGreen for uPA expression monitoring in pLNHXO5O6-TRE2-uPA-IRES-ZsGreen.The correct constructed plasmids were transfected into packaging cell line GP 2-293 to gain recombinant viral particles .NIH/3T3 cells were infected with these viral particles and selected with G 418.Gene expression in the surviving cells was confirmed by the PCR method .Results The recombinant retroviral vectors harbouring target genes were successfully cloned .The rtTA gene in pLNHXO1O2-Alb-GLUC-FMN2A-rtTA was expressed, and uPA can be induced to express in pLNHXO5O6-TRE2-uPA-IRES-ZsGreen by doxycycline (Dox) when the plasmid transfected into the HepG-Tet-on cell.The constructed recombinant two retroviral vectors were transfected into GP 2-293 packaging cells respectively to gain infectious viral particles .Then,NIH/3T3 cells were infected with these viral particles and single-cell clones which stably expressed the transgenes were successfully established .Conclusion This study primarily established uPA inducible expression system , it laid a foundation for the murine model of inducible liver damage , and provided a novel technical platform for further building the liver humanised murine models for viral hepatitis studying .