Lactoperoxidase (LPO) is a 78 kDa
heme-containing oxidation-reduction
enzyme present in milk, found in physiological fluids of mammals. LPO has an antimicrobial activity, and presumably contribute to the protective functions of milk against
infectious diseases. In this study, recombinant vaccinia virus expressing bovine LPO (vv/bLPO) was constructed. In rabbit kidney (RK13) cells infected with vv/bLPO, recombinant bLPO was detected in both
cell extracts and culture supernatants.
Tunicamycin treatment decreased the molecular weight of recombinant bLPO, indicating that recombinant bLPO contains a N-linked glycosylation site. The replication of recombinant vaccinia viruses expressing bovine
lactoferrin (vv/bLF) at a multiplicity of
infection (moi) of 5 plaque-forming units (PFU)/cell was inhibited by
antiviral activity of recombinant bLF, suggesting that vv/bLF has an
antiviral effect against vaccinia virus. On the other hand, the replication of vv/bLPO at a moi of 5 PFU/cell was not inhibited by
antiviral activity of recombinant bLPO, indicating that this recombinant virus could be used as a suitable viral vector. These results indicate that a combination of bLPO and vaccinia virus vector may be useful for medical and veterinary applications in vivo.