title: Serum antibody responses to equine herpesvirus 1 glycoprotein D in horses, pregnant mares and young foals.
abstract: The envelope glycoprotein D of equine herpesvirus 1 (EHV-1 gD) has been shown in laboratory animal models to elicit protective immune responses against EHV-1 challenge, and hence is a potential vaccine antigen. Here we report that intramuscular inoculation of EHV-1 gD produced by a recombinant baculovirus and formulated with the adjuvant Iscomatrix elicited virus-neutralizing antibody and gD-specific ELISA antibody in the serum of over 90% of adult mixed breed horses. The virus-neutralizing antibody responses to EHV-1 gD were similar to those observed after inoculation with a commercially available killed EHV-1/4 whole virus vaccine. Intramuscular inoculation of EHV-1 gD DNA encoded in a mammalian expression vector was less effective in inducing antibody responses when administered as the sole immunogen, but inoculation with EHV-1 gD DNA followed by recombinant EHV-1 gD induced increased gD ELISA and virus-neutralizing antibody titres in six out of seven horses. However, these titres were not higher than those induced by either EHV-1 gD or the whole virus vaccine. Isotype analysis revealed elevated gD-specific equine IgGa and IgGb relative to IgGc, IgG(T) and IgA in horses inoculated with EHV-1 gD or with the whole virus vaccine. Following inoculation of pregnant mares with EHV-1 gD, their foals had significantly higher levels of colostrally derived anti-gD antibody than foals out of uninoculated mares. The EHV-1 gD preparation did not induce a significant mean antibody response in neonatal foals following inoculation at 12 h post-partum and at 30 days of age, irrespective of the antibody status of the mare. The ability of EHV-1 gD to evoke comparable neutralizing antibody responses in horses to those of a whole virus vaccine confirms EHV-1 gD as a promising candidate for inclusion in subunit vaccines against EHV-1.
authors.affiliation: Department of Biological Sciences, Macquarie University, Sydney, NSW 2109, Australia.
authors.forename: C E
authors.initials: CE
authors.lastname: Foote
authors.forename: D N
authors.initials: DN
authors.lastname: Love
authors.forename: J R
authors.initials: JR
authors.lastname: Gilkerson
authors.forename: J
authors.initials: J
authors.lastname: Rota
authors.forename: P
authors.initials: P
authors.lastname: Trevor-Jones
authors.forename: K M
authors.initials: KM
authors.lastname: Ruitenberg
authors.forename: J E
authors.initials: JE
authors.lastname: Wellington
authors.forename: J M
authors.initials: JM
authors.lastname: Whalley
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D000914:Antibodies, Viral / Q000096:biosynthesis / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D006566:Herpesviridae Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary* / Q000821:virology; D004861:Herpesvirus 1, Equid / Q000276:immunology*; D006734:Horse Diseases / Q000276:immunology* / Q000517:prevention & control / Q000821:virology*; D006736:Horses; D007114:Immunization / Q000662:veterinary*; D009500:Neutralization Tests / Q000662:veterinary; D011247:Pregnancy; D011994:Recombinant Proteins / Q000276:immunology; D019444:Vaccines, DNA / Q000276:immunology; D022223:Vaccines, Subunit / Q000276:immunology; D014759:Viral Envelope Proteins / Q000276:immunology*; D014765:Viral Vaccines / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D000914:Antibodies, Viral; D011994:Recombinant Proteins; D019444:Vaccines, DNA; D022223:Vaccines, Subunit; D014759:Viral Envelope Proteins; D014765:Viral Vaccines; C488988:glycoprotein D, Equid herpesvirus 1