ABSTRACT
Recombinant DNA vaccines, based on plasmid vectors expressing an antigen under the control of a strong promotor, have several advantages over traditional vaccines. They have been shown to induce a full spectrum of immune responses for humoral and cellular systems and to secure the higher safety and the simplicity of administration. Thus, establishment of DNA vaccines against Newcastle disease virus (NDV) in poultry has been widely investigated using various virus strains and vector systems. In this study, the F and HN genes of NDV CBP-1 strains isolated from diseased pheasants and attenuated by serial passages in egg embryos were cloned using pSLIA vector and constructed two recombinants of pSLIA-tsF and pSLIA-tsHN. The recombinant plasmids were transfected into COS-7 cell and the expression of HN and F proteins were verified by immunofluorescence, SDS-PAGE and Western blot. The recombinant plasmids were injected intramuscularly and intradermally into C57B/6 mouse and a significant increment of HN and F antibodies was detected by ELISA. According to the results, it was implicative that the recombinant DNA could be utilized for development of recombinant DNA vaccine for NDV.
Subject(s)
Animals , Mice , Antibodies , Blotting, Western , Clone Cells , COS Cells , DNA, Recombinant , Electrophoresis, Polyacrylamide Gel , Embryonic Structures , Enzyme-Linked Immunosorbent Assay , Fluorescent Antibody Technique , Newcastle disease virus , Newcastle Disease , Ovum , Plasmids , Poultry , Serial Passage , Vaccines , Vaccines, DNAABSTRACT
Recent outbreaks of H5N1 avian influenza viruses in most Asian countries alert the imminent pandemic. Twenty-three humans out of 34 confirmed cases were dead of H5N1 infections. H9N2 avian influenza viruses are widespread in poultry in most Asian countries and infected humans in 1999 and 2003. H9N2 or H5N1 influenza viruses may cause a next pandemic. The extensive surveillance in poultry and pigs are very important for predicting a next pandemic. We performed the surveillance of avian influenza viruses in chickens sold in the live poultry markets. Only H9N2 subtypes of influenza viruses were isolated from chickens in the Korean live bird markets. Serological surveillance in chickens showed that chickens were infected with over 50% with H9N2 viruses. Antigenic analysis showed that current circulating H9N2 influenza viruses are distinct from those of Hong Kong and 1996 Korean isolates from chicken farms. Serological surveillance of pigs against H9N2 influenza viruses showed that over 20% are positive. To prepare the vaccine of H5N1 avian influenza viruses, reassortant viruses were made using the available reverse genetics. The efficacy and safety test of H5N1 candidate vaccine in monkeys showed that neutralization antibody were induced and no side effects such as fever and weight loss were observed.
Subject(s)
Animals , Humans , Asian People , Birds , Chickens , Disease Outbreaks , Fever , Haplorhini , Hong Kong , Influenza A Virus, H9N2 Subtype , Influenza in Birds , Orthomyxoviridae , Pandemics , Poultry , Reassortant Viruses , Reverse Genetics , Swine , Weight LossABSTRACT
Recent outbreaks of H5N1 avian influenza viruses in most Asian countries alert the imminent pandemic. Twenty-three humans out of 34 confirmed cases were dead of H5N1 infections. H9N2 avian influenza viruses are widespread in poultry in most Asian countries and infected humans in 1999 and 2003. H9N2 or H5N1 influenza viruses may cause a next pandemic. The extensive surveillance in poultry and pigs are very important for predicting a next pandemic. We performed the surveillance of avian influenza viruses in chickens sold in the live poultry markets. Only H9N2 subtypes of influenza viruses were isolated from chickens in the Korean live bird markets. Serological surveillance in chickens showed that chickens were infected with over 50% with H9N2 viruses. Antigenic analysis showed that current circulating H9N2 influenza viruses are distinct from those of Hong Kong and 1996 Korean isolates from chicken farms. Serological surveillance of pigs against H9N2 influenza viruses showed that over 20% are positive. To prepare the vaccine of H5N1 avian influenza viruses, reassortant viruses were made using the available reverse genetics. The efficacy and safety test of H5N1 candidate vaccine in monkeys showed that neutralization antibody were induced and no side effects such as fever and weight loss were observed.