RESUMO
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.