Genetic immunisation of cattle against bovine herpesvirus 1: glycoprotein gD confers higher protection than glycoprotein gC or tegument protein VP8.
Bovine herpesvirus 1 (BoHV-1) has frequently been used as a model for testing parameters affecting DNA immunisation in large animals like cattle. However, the selection of target antigens has been poorly studied, and most of the experiments have been conducted in mice. In the present study, we demonstrated in cattle that a DNA vaccine encoding BoHV-1 glycoprotein gD induces higher neutralising antibody titres than vaccines encoding BoHV-1 gC. Additionally, we show that a DNA vaccine encoding a secreted form of gD induces a higher immune response than a vaccine encoding full-length gD. However, the enhanced immunogenicity associated with the secretion of gD could not be extended to the glycoprotein gC. The current study also describes for the first time the development and the evaluation of a DNA vaccine encoding the major tegument protein VP8. This construct, which is the first BoHV-1 plasmid vaccine candidate that is not directed against a surface glycoprotein, induced a high BoHV-1 specific cellular immunity but no humoral immune response. The calves vaccinated with the constructs encoding full-length and truncated gD showed a non-significant tenfold reduction of virus excretion after challenge. Those calves also excreted virus for significantly (p < 0.05) shorter periods (1.5 days) than the non-vaccinated controls. The other constructs encoding gC and VP8 antigens induced no virological protection as compared to controls. Altogether the DNA vaccines induced weaker immunity and protection than conventional marker vaccines tested previously, confirming the difficulty to develop efficient DNA vaccines in large species.
Toussaint
Jean-François
JF
Veterinary and Agrochemical Research Centre, Department of Virology, Groeselenberg 99, 1180 Brussels, Belgium. jetou@var.fgov.be
Coen
Laurent
L
Letellier
Carine
C
Dispas
Marc
M
Gillet
Laurent
L
Vanderplasschen
Alain
A
Kerkhofs
Pierre
P
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D036022:Capsid Proteins / Q000276:immunology; D002417:Cattle / Q000276:immunology*; D002460:Cell Line; D006023:Glycoproteins / Q000276:immunology; D007242:Herpesvirus 1, Bovine / Q000276:immunology*; D022283:Herpesvirus Vaccines / Q000276:immunology*; D013997:Time Factors; D019444:Vaccines, DNA / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000276:immunology
D000914:Antibodies, Viral; D036022:Capsid Proteins; D006023:Glycoproteins; D022283:Herpesvirus Vaccines; C442561:VP8 protein, Bovine herpesvirus 1; D019444:Vaccines, DNA; D014759:Viral Envelope Proteins