Compatibility of plasmids encoding bovine viral diarrhea virus type 1 and type 2 E2 in a single DNA vaccine formulation.
Type 2 bovine viral diarrhea virus (BVDV) has become increasingly prevalent worldwide, and currently the ratio of type 2 to type 1 strains in the USA approaches 50%. Although there is cross-reactivity between BVDV type 1 and type 2 strains, BVDV1 vaccine strains poorly protect from type 2 infection, so vaccines against BVDV should contain antigens from both BVDV types. Previously we demonstrated efficacy of a BVDV1 E2 DNA vaccine, and in this study we optimized a BVDV2 E2 DNA vaccine. Furthermore, as an approach to vaccinate with a DNA vaccine against both BVDV types, we compared two strategies, mixing of plasmids encoding type 1 and type 2 E2, and co-expression of type 1 and type 2 E2 from one plasmid with an internal ribosomal entry site (IRES). An evaluation of the IRES-containing plasmids demonstrated that the C-terminally expressed protein is produced at lower levels and induces weaker immune responses than the N-terminally expressed protein, regardless of the position of the type 1 and type 2 E2 genes. In contrast, when both plasmids encoding type 1 and type 2 E2 were administered to mice, the immune responses were similar to those induced by the individual plasmids. Thus, a mixture of plasmids encoding type 1 and type 2 E2 could be a potential DNA vaccine candidate against both BVDV1 and BVDV2.
Liang
Rong
R
Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, 120 Veterinary Road, Saskatoon, Sask. S7N 5E3, Canada.
Babiuk
Lorne A
LA
van Drunen Littel-van den Hurk
Sylvia
S
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001912:Bovine Virus Diarrhea-Mucosal Disease / Q000517:prevention & control; D002417:Cattle; D002460:Cell Line; D030241:Diarrhea Virus 1, Bovine Viral / Q000235:genetics / Q000276:immunology*; D030242:Diarrhea Virus 2, Bovine Viral / Q000235:genetics / Q000276:immunology*; D015967:Gene Expression Regulation, Viral; D006801:Humans; D051379:Mice; D010957:Plasmids / Q000235:genetics*; D019444:Vaccines, DNA / Q000235:genetics* / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000235:genetics* / Q000378:metabolism; D014765:Viral Vaccines / Q000235:genetics* / Q000276:immunology*
D000914:Antibodies, Viral; D019444:Vaccines, DNA; D014759:Viral Envelope Proteins; D014765:Viral Vaccines; C076551:gp53, bovine viral diarrhea virus