Construction and Immunogenicity of Recombinant Canine Adenovirus Type 2 of Feline Distemper Virus VP2

In order to construct a recombinant canine adenovirus type 2 (CAV-2) of the VP2 of Feline distemper virus or Feline panleukopenia virus (FPV), the vp2 gene fragment of FPV GT-2 strain was amplified by PCR and cloned into pVAX1 vector. The complete VP2 expression cassette was subcloned into the shuttle vector pVAXΔE3 and then inserted into the pPoly2-CAV-2 backbone vector that contains the complete genome of CAV-2. Recombinant viral genome was linearized by ClaI/AscI and transfected into MDCK cell. The recombinant CAV-2-VP2 was a-chieved through 4 passages in MDCK, which showed typical cytopathogenic effect (CPE). The expressed FPV VP-2 was detected in the infected MDCK cells of the recombinant CAV-2-VP-2 by using FPV polyclonal antibodies. The specific antibodies of VP-2 and CAV-2 were induced in cats by the recombinant CAV-2-VP-2. The results indicated that the recombinant CAV-2-VP-2 may have the potential to be used as a FPV vaccine strain.