Deletion of gene 52 encoding glycoprotein M of equine herpesvirus type 1 strain RacH results in increased immunogenicity.
The immunogenicity of equine herpesvirus type 1 (EHV-1) strain RacH was compared to a RacH virus in which gene 52 encoding glycoprotein M (gM) was interrupted by insertion of LacZ (HDeltagM-Ins) and a RacH with 75% of gene 52 was deleted and replaced by LacZ (HDeltagM-HS). HDeltagM-Ins failed to produce full-length gM, but the carboxy-terminal portion was still expressed. No gM expression was detected in HDeltagM-HS-infected cells. Mice were immunised once with 1x10(3) to 1x10(5) plaque-forming units (PFU) of RacH or mutant viruses and challenged with virulent RacL11 virus 29 days later. A dose-dependence of protection was observed in RacH-immunised mice, and following immunisation with 1x10(4) or 1x10(3) PFU body weight losses and increased virus titres in lungs were observed after challenge infection. HDeltagM-HS-immunised mice were completely protected even after immunisation with 1x10(3) PFU. Mice immunised with 1x10(3) PFU of HDeltagM-Ins but not the higher doses showed signs of disease after challenge infection.
Osterrieder
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N
Federal Research Centre for Virus Diseases of Animals, Institute of Molecular Biology, Friedrich-Loeffler-Institutes, Boddenblick 5a, D-17498, Insel Riems, Germany. klaus.osterrieder@rie.bfav.de
Seyboldt
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C
Elbers
K
K
D000818:Animals; D004306:Dose-Response Relationship, Immunologic; D017353:Gene Deletion; D015870:Gene Expression; D006566:Herpesviridae Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D004861:Herpesvirus 1, Equid / Q000235:genetics* / Q000276:immunology*; D006734:Horse Diseases / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D006736:Horses; D008563:Membrane Lipids / Q000235:genetics / Q000276:immunology; D051379:Mice; D009154:Mutation; D014759:Viral Envelope Proteins / Q000235:genetics* / Q000276:immunology*; D010948:Viral Plaque Assay; D014765:Viral Vaccines
D008563:Membrane Lipids; D014759:Viral Envelope Proteins; D014765:Viral Vaccines; C418522:glycoprotein M, Equid herpesvirus 1; C050629:viral envelope lipids