title: Priming with DNA encoding E2 and boosting with E2 protein formulated with CpG oligodeoxynucleotides induces strong immune responses and protection from Bovine viral diarrhea virus in cattle.
abstract: The objective of this study was to develop an optimal vaccination strategy for Bovine viral diarrhea virus (BVDV). The E2 protein of BVDV plays a major protective role against BVDV infection. In order to be able to compare DNA, protein and DNA prime-protein boost regimens, a plasmid was constructed encoding a secreted form of the NADL strain E2 protein (pMASIA-tPAsDeltaE2). Furthermore, a pure secreted recombinant DeltaE2 (rDeltaE2) protein was produced. The rDeltaE2 protein was formulated with a combination of Emulsigen and CpG oligodeoxynucleotide. Groups of calves were immunized with pMASIA-tPAsDeltaE2 or with rDeltaE2, or first with pMASIA-tPAsDeltaE2 and then with rDeltaE2. To evaluate the protection against BVDV, calves were challenged with BVDV strain NY-1 after the last immunization. Although all immunized calves developed humoral and cellular immune responses, the antibody responses in the DNA prime-protein boost group were stronger than those elicited by either the DNA vaccine or the protein vaccine. In particular, E2-specific antibody titres were enhanced significantly after boosting the DeltaE2 DNA-primed calves with rDeltaE2 protein. Moreover, protection against BVDV challenge was obtained in the calves treated with the DNA prime-protein boost vaccination regimen, as shown by a significant reduction in weight loss, viral excretion and lymphopenia, compared with the unvaccinated calves and the animals immunized with the DNA or protein only. These results demonstrate the advantage of a DNA prime-protein boost vaccination approach in an outbred species.
authors.affiliation: Vaccine and Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Road, SK S7N 5E3, Canada.
authors.forename: Rong
authors.initials: R
authors.lastname: Liang
authors.affiliation: Vaccine and Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Road, SK S7N 5E3, Canada.
authors.forename: Jan V
authors.initials: JV
authors.lastname: van den Hurk
authors.affiliation: Vaccine and Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Road, SK S7N 5E3, Canada.
authors.forename: Lorne A
authors.initials: LA
authors.lastname: Babiuk
authors.affiliation: Vaccine and Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Road, SK S7N 5E3, Canada.
authors.forename: Sylvia
authors.initials: S
authors.lastname: van Drunen Littel-van den Hurk
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001835:Body Weight; D001912:Bovine Virus Diarrhea-Mucosal Disease / Q000517:prevention & control; D019556:COS Cells; D002417:Cattle; D002460:Cell Line; D002522:Chlorocebus aethiops; D018899:CpG Islands / Q000276:immunology*; D004279:DNA, Viral / Q000276:immunology*; D001908:Diarrhea Viruses, Bovine Viral / Q000276:immunology*; D007074:Immunoglobulin G / Q000097:blood; D007962:Leukocytes / Q000821:virology; D009666:Nose / Q000821:virology; D014759:Viral Envelope Proteins / Q000276:immunology*; D014765:Viral Vaccines / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D004279:DNA, Viral; D007074:Immunoglobulin G; D014759:Viral Envelope Proteins; D014765:Viral Vaccines; C076551:gp53, bovine viral diarrhea virus