Objective      To construct the adenovirus vector carrying methyl-CpG binding domain 2 (MBD2) gene and express this gene in human submandibular gland (HSG）cell line.       Methods      cDNA fragment encoding human MBD2 gene was amplified by reverse transcriptase-polymerase chain reaction (RT-PCR) with the total mRNA isolated from HSG cells as template. The PCR amplified product was first cloned into pMD18-T vector

and then subcloned into the shuttle vector pAdTrack-CMV in order to construct the recombinant plasmids pAdTrack-MBD2

which homologously recombinated with the adenoviral backbone vectors Adeasy-1 in BJ5183 bacterial cells

so as to generate recombinant adenoviral plasmids Ad-MBD2. The recombinant adenoviruses Ad/MBD2

which were employed to infect HSG cells

were generated by transfecting the recombinant adenoviral DNA into 293 cells. The growth of transfected HSG cells and the expression of enhanced green fluorescent protein (EGFP) were observed by invert microscopy. Image analysis was employed to calculate the transfection efficiency. Subsequently the expression of MBD2 in transfected HSG cells was tested by RT-PCR.       Results      Human MBD2 gene fragment

with a length of 909 bp

was successfully cloned

and recombinant adenoviral vector of Ad/MBD2 was constructed. The recombinant adenoviruses Ad/MBD2 were ge-nerated by transfecting the recombinant adenoviral DNA into 293 cells. Adenoviral virus particle which possessed infectious competent was made from Ad/MBD2. Its transfection efficiency was about 70%. HSG cells expressed MBD2 gene obviously after infection.       Conclusion      Human MBD2 gene is successfully cloned

and recombinant adenoviral vector of Ad/MBD2 is constructed. The valid expression of MBD2 gene in HSG cells has been confirmed.