Construction Of Recombinant Fowlpox Virus Expressing NA1, NA2 Of Avain Influenza Virus

The results manifested the obtained rFPV-NA1 and rFPV-NA2 had stable hereditary Avian influenza virus A/Goose/Guangdong/1/96(H5N1) NA gene was cut from the plasmid of PMD18-TNA, then subcloned into vector pSY538, which contained fowlpox virus early/late promoter LP2EP2, then LacZ was cloned into it. The fragments of NA and LacZ were subcloned into pSY681, then the transfer vector was constructed .By lipfectamine chicken embryo fibroblast (CEF) cell cultures which were infected with S-FPV-017 were transfected with the complex of pSY681NALacZ plasmid. Recombinant FPV was selected by blue plaque,base on the expressing LacZ gene, following several times cycles of plaque purification, identification of PCR, the results showed that a pure recombinant fowlpox virus NA1 gene(rFPV-NA1)was obtained. Avian influenza virus A/Chicken/Guangdong/21/02(H9N2) NA2 gene was amplified from the plamid PBD-NA2 and cloned into SmaI site of vector PCAGG, parallely vector pSY538 was cut by EcoRI and BamHI., then NA2 gene was cut from PCAGG and subcloned into vector pSY538. The following approaches were same as the construction of NA1 recombinant fowlpox virus. The result showed that a pure recombinant fowlpox virus NA2 gene (rFPV-NA2) was obtained. character and could express effectively. The expressed products in cells were similar to AIV proteins in biological character.Protection study was performed with five weeks old SPF chickens. Chickens were challenged with a lethal dose of HPAIVLN/02(H5N1) and A/FPV/Rostock/34(H7N1).After H5N1 challenged, all chickens immunized with rFPV-NA1 or rFPV-NA2 were dead; H7N1 challenged, 13.3% chickens immunized with rFPV-NA1 were protected from death while all chickens immunized with rFPV-NA2 were dead. In control group, 100% SPF chickens were dead.