[Characterization of a recombinant goatpox virus expressing Orfv F1L gene]

In order to establish the vaccine against the contagious ecthyma, we constructed and characterized recombinant goatpox virus expressing F1L protein of Orf virus.

The F1L gene was amplified and cloned into the vector pUC-TK12 carrying the LacZ gene and a bidirectional promoter. With the help of lipidosome, the recombinant plasmid pTL-F1L was transfected into the BHK-21 cells, which had been infected by Gpv. The aim is to make the Gpv and pTL-F1L recombined randomly and get the recombinant virus, which was defined as rGpv-F1L. The rGpv-F1L was screened by blue plaque, and then the F1L recombination and translation were identified by PCR, indirect immunofluorescence and Western blot. By the means of TCID50, we evaluated the physicochemical properties of rGpv-F1L. Female mice were immunized with the rGpv-F1L, and the specific antibodies levels in serum were detected by ELISA.

We obtained rGpv-F1L, which was stably expressing F1L protein. The results of biological characteristics showed the rGpv-F1L was sensitive to acids, alkalis, organic solvents and ultraviolet. The activity of specific antibodies significantly increased in mice infected by rGpv-F1L more than Gpv (P < 0.01).

In this research, we have successfully obtained the candidate vaccine, which is stably expressing F1L of Orf virus. Thereby the candidate vaccine with excellent antigenicity and biological activity provides new avenues for the prevention of contagious ecthyma and capripox.