title: Experimental infection with equine herpesvirus type 1 (EHV-1) induces chorioretinal lesions.
abstract: Equine herpesvirus myeloencephalitis (EHM) remains one of the most devastating manifestations of equine herpesvirus type 1 (EHV-1) infection but our understanding of its pathogenesis remains rudimentary, partly because of a lack of adequate experimental models. EHV-1 infection of the ocular vasculature may offer an alternative model as EHV-1-induced chorioretinopathy appears to occur in a significant number of horses, and the pathogenesis of EHM and ocular EHV-1 may be similar. To investigate the potential of ocular EHV-1 as a model for EHM, and to determine the frequency of ocular EHV-1, our goal was to study: (1) Dissemination of virus following acute infection, (2) Development and frequency of ocular lesions following infection, and (3) Utility of a GFP-expressing virus for localization of the virus in vivo. Viral antigen could be detected following acute infection in ocular tissues and the central nervous system (experiment 1). Furthermore, EHV-1 infection resulted in multifocal choroidal lesions in 90% (experiment 2) and 50% (experiment 3) of experimentally infected horses, however ocular lesions did not appear in vivo until between 3 weeks and 3 months post-infection. Taken together, the timing of the appearance of lesions and their ophthalmoscopic features suggest that their pathogenesis may involve ischemic injury to the chorioretina following viremic delivery of virus to the eye, mirroring the vascular events that result in EHM. In summary, we show that the frequency of ocular EHV-1 is 50-90% following experimental infection making this model attractive for testing future vaccines or therapeutics in an immunologically relevant age group.
authors.affiliation: Department of Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing, MI 48824, USA. husseygi@msu.edu.
authors.forename: Gisela Soboll
authors.initials: GS
authors.lastname: Hussey
authors.forename: Lutz S
authors.initials: LS
authors.lastname: Goehring
authors.forename: David P
authors.initials: DP
authors.lastname: Lunn
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Hussey
authors.forename: Teng
authors.initials: T
authors.lastname: Huang
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Osterrieder
authors.forename: Cynthia
authors.initials: C
authors.lastname: Powell
authors.forename: Jesse
authors.initials: J
authors.lastname: Hand
authors.forename: Carine
authors.initials: C
authors.lastname: Holz
authors.forename: Josh
authors.initials: J
authors.lastname: Slater
mesh_terms: D000818:Animals; D002825:Chorioretinitis / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary* / Q000821:virology; D004679:Encephalomyelitis / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary* / Q000821:virology; D005451:Fluorescein Angiography / Q000379:methods* / Q000662:veterinary; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006566:Herpesviridae Infections / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary* / Q000821:virology; D004861:Herpesvirus 1, Equid / Q000302:isolation & purification*; D006734:Horse Diseases / Q000453:epidemiology / Q000473:pathology / Q000821:virology; D006736:Horses; D009500:Neutralization Tests / Q000662:veterinary; D009666:Nose / Q000821:virology; D011897:Random Allocation; D014766:Viremia / Q000662:veterinary / Q000821:virology; D017201:Virus Shedding
chemical_list: C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins