Infectious bovine viral diarrhea virus (BVDV) cDNA clones have been used for the expression of classical swine fever virus (CSFV) genes for immune prevention and control However, can it be used for the expression of an allogenetic fragment? To answer this question, a BVDV chimeric virus expressing the spike (S) antigen fragment of porcine epidemic diarrhea virus (PEDV) was constructed Antigen Ssub499-602/sub was inserted into pig-derived BVDV-2 infectious cDNA clone pASH28 in tandem by overlapping PCR, located between the seventh and eighth amino acids at the N-terminus of the capsid (C) protein of BVDV Indirect immunofluorescence assay confirmed that the chimeric virus vASH-dS312 containing double Ssub499-602/sub sequences was successfully assembled, which could react with the monoclonal antibody (MAb) against BVDV E2 and PEDV S proteins Further western blot analysis confirmed that the exogenous Ssub499-602/sub double protein could be stably expressed Next, the chimeric virus vASH-dS312 was administered to BALB/C mice either orally or by intramuscular injection The immunized mice were healthy and showed no signs of toxicity IgG against BVDV and PEDV antibodies could be detected in the mice administered vASH-dS312 by intramuscular injection, which had neutralization activity against BVDV and PEDV Thus, this study reported a new insertion site in the BVDV infectious cDNA clone that could successfully express an allogenetic antigen
Attenuated porcine-derived type 2 bovine viral diarrhea virus as vector stably expressing viral gene