A subunit gIV vaccine, produced by transfected mammalian cells in culture, induces mucosal immunity against bovine herpesvirus-1 in cattle.
A truncated version of bovine herpesvirus-1 (BHV-1) glycoprotein IV (tgIV) was produced in a novel, non-destructive expression system based upon regulation of gene expression by the bovine heat-shock protein 70A (hsp70) gene promoter in Madin Darby bovine kidney (MDBK) cells. In this system, up to 20 micrograms ml-1 of secreted tgIV, which is equivalent to the yield from 4 x 10(6) cells, was produced daily over a period of up to 18 days. Different doses of tgIV were injected intramuscularly into seronegative calves. Virus-neutralizing antibodies were induced by all doses of tgIV, both in the serum and in the nasal superficial mucosa. However, the low dose (2.3 micrograms) induced significantly (p < 0.05) lower antibody titres than the medium (7 micrograms) and high (21 micrograms) doses. The medium and high doses of tgIV conferred protection from BHV-1 infection, as demonstrated by a significant (p < 0.05) reduction in clinical signs of respiratory disease and virus shedding in the nasal secretions postchallenge. However, the 2.3 micrograms group, although partially protected, was not significantly (p > 0.05) different from the placebo group. This study demonstrated the potential of an intramuscularly administered tgIV subunit vaccine to induce mucosal immunity to BHV-1 using an economic protein production system and an acceptable vaccine formulation. In addition, a strong correlation was observed between neutralizing antibodies in the serum and nasal superficial mucosa, virus shedding and clinical disease. Thus, serum neutralizing antibody levels in tgIV-immunized animals may be a good prognosticator of protection from BHV-1 infection and disease.
van Drunen Littel-van den Hurk
S
S
Veterinary Infectious Disease Organization, University of Saskatchewan, Saskatoon, Canada.
Van Donkersgoed
J
J
Kowalski
J
J
van den Hurk
J V
JV
Harland
R
R
Babiuk
L A
LA
Zamb
T J
TJ
D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis* / Q000097:blood; D015153:Blotting, Western / Q000662:veterinary; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology* / Q000517:prevention & control; D002460:Cell Line; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D006566:Herpesviridae Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D007242:Herpesvirus 1, Bovine / Q000276:immunology*; D009297:Nasal Mucosa / Q000276:immunology; D009500:Neutralization Tests / Q000662:veterinary; D014162:Transfection; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000096:biosynthesis / Q000276:immunology; D014764:Viral Proteins / Q000008:administration & dosage / Q000096:biosynthesis / Q000276:immunology*; D014765:Viral Vaccines / Q000276:immunology*
D000914:Antibodies, Viral; D014614:Vaccines, Synthetic; D014764:Viral Proteins; D014765:Viral Vaccines; C046998:bovine herpesvirus type-1 glycoproteins