title: Epitope specificity is critical for high and moderate avidity cytotoxic T lymphocytes associated with control of viral load and clinical disease in horses with equine infectious anemia virus.
abstract: Equine infectious anemia virus (EIAV) is a lentivirus that causes persistent infections in horses. We hypothesized that high-avidity CTL specific for nonvariable epitopes might be associated with low viral load and minimal disease in EIAV-infected horses. To test this hypothesis, memory CTL (CTLm) responses were analyzed in two infected horses with high plasma viral loads and recurrent disease (progressors), and in two infected horses with low-to-undetectable viral loads and mild disease (nonprogressors). High-avidity CTLm in one progressor recognized an envelope gp90 epitope, and the data documented for the first time in EIAV that viral variation led to CTL escape. Each of the nonprogressors had high-to-moderate avidity CTLm directed against epitopes within Rev, including the nuclear export and nuclear localization domains. These results suggested that the epitope specificity of high- and moderate-avidity CTLm was an important determinant for disease outcome in the EIAV-infected horses examined.
authors.affiliation: Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164-7040, USA. rhm@vetmed.wsu.edu
authors.forename: Robert H
authors.initials: RH
authors.lastname: Mealey
authors.forename: Baoshan
authors.initials: B
authors.lastname: Zhang
authors.forename: Steven R
authors.initials: SR
authors.lastname: Leib
authors.forename: Matt H
authors.initials: MH
authors.lastname: Littke
authors.forename: Travis C
authors.initials: TC
authors.lastname: McGuire
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018450:Disease Progression; D018604:Epitope Mapping; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D004859:Equine Infectious Anemia / Q000175:diagnosis / Q000276:immunology* / Q000821:virology; D005334:Fever / Q000662:veterinary; D006023:Glycoproteins / Q000235:genetics / Q000276:immunology*; D006736:Horses; D007156:Immunologic Memory; D004860:Infectious Anemia Virus, Equine / Q000737:chemistry; D008969:Molecular Sequence Data; D012367:RNA, Viral / Q000032:analysis; D016415:Sequence Alignment; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D013921:Thrombocytopenia / Q000662:veterinary; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology*; D019562:Viral Load / Q000662:veterinary
chemical_list: D018984:Epitopes, T-Lymphocyte; D006023:Glycoproteins; D012367:RNA, Viral; C091940:SU protein, equine infectious anemia virus; D014759:Viral Envelope Proteins