Objective    To construct a eukaryotic expression vector containing mouse IDO gene fused with enhanced green fluorescent protein (pEGFP-N1) and its expression in immature DCs.     Methods    The full-length IDO gene was obtained from mouse by RT-PCR and was inserted into eukaryotic expression vector pEGFP-N1. After identified by restriction digestion and sequencing

the recombinant pEGFP-N1-IDO was transfected into immature DCs by DOTAP liposome. After screened by G418

the green fluorescence protein expression in immature DCs was observed under inverted fluorescence microscope and the mRNA and protein expressions of IDO were respectively detected by RT-PCR and Western blot.      Results    The full-length sequence of IDO was successfully inserted into the eukaryotic expression vector pEGFP-N1 and confirmed by restriction digestion and sequencing. The recombinant was successfully transfected into immature DCs and the IDO gene was expressed.     Conclusion    The eukaryotic expression vector pEGFP-N1-IDO was constructed successfully and IDO gene could be expressed efficiently in immature transfected DCs.