[Immunity and EGFPC3 expression of recombinant attenuated salmonella typhimurium carrying plasmid pcDNA3s and EGFPC3 in mice].

Aim: To study the immune characterization of HBsAg DNA recombinant attenuated salmonella typhimurium vaccine and the expression of enhanced green fluorescence protein gene pEGFPC3 in mice.

Methods: Plasmid pcDNA3s and pEGFPC3 was transformed into attenuated salmonella typhimurium SL8786 by electricity instrument to construct recombinant vaccine SL8786/EGFPC3 and SL8786/pcDNA3s. Mice were immunized with the recombinant vaccine and the quantity of anti-HBs antibody in the sera was measured by time resolved fluorescence immunoassay(TRFIA), While the cytotoxocity of CTL was measured by LDH release assay.

Results: It produced strong specificity CTL response after taking SL8786/pcDNA3s orally to mice and anti-HBs was highest in 11 weeks. EGFPC3 expression in two mice spleen cells was detected by flow cytometry(FCM). EGFP masculine ratio is 19.20% and 17.36% respectively. but SL8786/pcDNA3 in two mice spleens cell EGFP masculine ratio only is 1.95% and 1.63%. The mice was taken SL8786/EGFPC3 orally after three weeks, fluorescence expression in its liver, spleen, kidney, chest gland, duodenum, muscle, etc. were observed.

Conclusion: HBV DNA vaccine can induce specific cellular and humoral immune responses in vivo in mice by oral. Recombinant attenuated salmonella typhimurium SL8786/EGFPC3 we constructed. It has green fluorescence expression in mice's partial organization, and it offers a model for research gene engineering vaccine.