ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the expression of recombinant plasmid pcDNA3.1/GBD of glucan binding protein of Streptococcus mutans in mammalian cells COS-7.</p><p><b>METHODS</b>Eukaryotic plasmid carrying encoding gene of GBD of Streptococcus mutans gbpA was constructed and the plasmid was introduced into COS-7 cells by Lipofectamine reagent. The transient expressed protein in COS-7 cells was detected by immunochemistry technique.</p><p><b>RESULTS</b>The positive expression was detected in plasma of the cells which were transfected with recombinant plasmid pcDNA3.1/GBD. The cells which were transfected with pcDNA3.1 were negative.</p><p><b>CONCLUSION</b>GBD can translate and express in COS-7 cells after transfected with recombinant plasmid pcDNA3.1/GBD. The expressed protein locates in the plasma and the protein is able to combine with anti-GbpA antibody. The expressed protein has the antigenicity and is a candidate gene vaccine.</p>