CPB 697 RESEARCH SEMINAR
Yung-Yi Chen,
Graduate Student in Microbiology
Department of Comparative Pathobiology
“Immunogenicity Of Fusion Protein Expressed By DNA Encoding Infectious Bursal Disease
Virus Large Segment
Gene And Avian Influenza Virus Hemagglutinin Gene”
Thursday, April 3, 2008
VPTH
112
3:30
pm
Abstract:
DNA vaccine coding for infectious bursal disease virus (IBDV) large segment gene and that for avian influenza virus (AIV) hemagglutinin (HA) gene have been shown to induce immunity and provide protection against the respective disease. The present study was carried out to determine whether an IBDV large segment gene-based DNA fused with AIV HA gene could trigger immune response to both IBDV and AIV. Hemagglutinin gene of AIV was amplified from cDNA of A/turkey/WI/68 (H5N9) strain by PCR and inserted into IBDV VP3 gene in a vector carrying IBDV VP243 gene. The VP243-H5 fusion gene was subcloned to pcDNA vector. Protein expressed by the constructed plasmid was detected as bright green fluorescence in the transfected Vero cells by immunofluorescent antibody assay (IFA) using specific monoclonal antibody to IBDV VP2 or polyclonal antibody to AIV HA. One-day-old specific pathogen free (SPF) chickens were intramuscularly injected with 500 μg of vector DNA or plasmid DNA carrying VP243, H5, or VP243-H5 gene weekly for three times, followed by a two-week interval for the fourth injection. Sera were collected from DNA-vaccinated chickens weekly for 6 times after the second injection. Chickens inoculated with VP243/pcDNA had significantly higher (p<0.05) enzyme-linked immunosorbent assay (ELISA) titer to IBDV than those with VP243-H5/pcDNA 3 to 6 weeks after the first inoculation. The virus neutralization (VN) titers to IBDV were significantly higher (p<0.05) in chickens inoculated with VP243/pcDNA than those with VP243-H5/pcDNA 2 to 6 weeks after the first inoculation. The hemagglutination inhibition (HI) titers to AIV were significantly higher (p<0.05) in chickens inoculated with H5/pcDNA than those with VP243-H5/pcDNA 2 to 6 weeks after the first inoculation. The results indicated that IBDV large segment gene-based DNA fused with AIV HA gene in DNA vaccination can elicit specific neutralizing antibody response to both IBDV and AIV.