A PRELIMINARY STUDY ON IMMUNE RESPONSE TO HEPATITIS E VIRUS DNA VACCINE IN MICE

摘要

Objective. In order to elicit immune response to hepatitis E virus (HEV) with the method of direct injection of naked DNA. Methods. The gene encoding the structural protein of pORF3, a Chinese strain of HEV, was cloned into the eukaryotic expression plasmid pSVL. The resulted plasmid pSVL-HEV ORF3 was used as HEV DNA vaccine, to inoculate Balb/c mice intramuscularly with a dose of 100 μg. Mice injected with empty pSVL DNA served as control. Results. After 1-2 times inoculation, twelve of 16 mice inoculated with pSVL-HEV ORF3 had anti-HEV IgG seroconversion. pSVL-HEV ORF3 was still detectable in the muscle of the inoculated mice 18 days after the injection, by the method of PCR. None of the control group had a detectable level of anti-HEV IgG. It is also found that the humoral immune response to HEV induced by DNA vaccine could be boostered by HEV recombinant fusion protein. Conclusion. Our present study demonstrated that nucleic acid vaccine is able to prime a specific humoral immune response to HEV in mice.