title: Immunogenicity of recombinant VP2 proteins of all nine serotypes of African horse sickness virus.
abstract: African horse sickness (AHS) is an equine disease with a mortality of up to 90% for susceptible horses. The causative agent AHS virus (AHSV) is transmitted by species of Culicoides. AHSV serogroup within the genus Orbivirus of the Reoviridae family consists of nine serotypes that show no or very limited cross-neutralization. Of the seven structural proteins (VP1-VP7) of AHSV, VP2 is the serotype specific protein, and the major target for neutralizing antibodies. In this report, recombinant VP2 proteins of all nine serotypes were expressed individually by the baculovirus expression system and the immunogenicity of each was studied by immunization of guinea pigs with single VP2 as well as with cocktails of VP2 proteins. Homologous neutralizing antibodies measured by 50% plaque reduction assay showed varying degrees (from 37 to 1365) of titers for different VP2 proteins. A low cross-neutralizing antibody titer was found for genetically related AHSV serotypes. Immunization with VP2 cocktails containing equal amounts of each of the VP2 proteins also triggered neutralizing antibodies albeit to lower titers (4-117) to each of the serotypes in the cocktail. This study is a first step to develop a VP2 subunit vaccine for AHS and our results indicate that VP2 subunit vaccines are feasible individually or in a multi-serotype cocktail.
authors.affiliation: Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Kanai
authors.affiliation: Department of Virology, Central Veterinary Institute of Wageningen University (CVI), PO Box 65, 8200 AB Lelystad, The Netherlands; Department of Biochemistry, Centre for Human Metabonomics, North-West University, Private Bag X6001, Potchefstroom 2520, South Africa.
authors.forename: Piet A
authors.initials: PA
authors.lastname: van Rijn
authors.affiliation: Department of Virology, Central Veterinary Institute of Wageningen University (CVI), PO Box 65, 8200 AB Lelystad, The Netherlands.
authors.forename: Mieke
authors.initials: M
authors.lastname: Maris-Veldhuis
authors.affiliation: Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kaname
authors.affiliation: Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom.
authors.forename: T N
authors.initials: TN
authors.lastname: Athmaram
authors.affiliation: Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom. Electronic address: polly.roy@lshtm.ac.uk.
authors.forename: Polly
authors.initials: P
authors.lastname: Roy
mesh_terms: D000355:African Horse Sickness / Q000517:prevention & control*; D000356:African Horse Sickness Virus / Q000145:classification; D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D016367:Baculoviridae; D036022:Capsid Proteins / Q000276:immunology*; D005260:Female; D006168:Guinea Pigs; D009500:Neutralization Tests; D011994:Recombinant Proteins / Q000276:immunology; D065288:Serogroup; D022223:Vaccines, Subunit / Q000276:immunology; D014765:Viral Vaccines / Q000276:immunology*
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D036022:Capsid Proteins; D011994:Recombinant Proteins; C442519:VP2 protein, African horse sickness virus; D022223:Vaccines, Subunit; D014765:Viral Vaccines
keywords: African horse sickness; Capsid protein VP2; Recombinant protein; Subunit vaccine