title: Epitope shifting of gp90-specific cellular immune responses in EIAV-infected ponies.
abstract: Unlike other lentiviruses, EIAV replication can be controlled in most infected horses leading to an inapparent carrier state free of overt clinical signs which lasts for many years. While the resolution of the initial infection is correlated with the appearance of virus specific cellular immune responses, the precise immune mechanisms responsible for control of the infection are not yet identified. Since the virus undergoes rapid mutation following infection, the immune response must also adapt to meet this challenge. We hypothesize that this adaptation involves peptide-specific recognition shifting from immunodominant variable determinants to conserved immunorecessive determinants following EIAV infection. Forty-four peptides, spanning the entire surface unit protein (gp90) of EIAV, were used to monitor peptide-specific T cell responses in vivo over a six-month period following infection. Peptides were injected intradermally and punch biopsies were collected for real-time PCR analysis to monitor the cellular peptide-specific immune responses in vivo. Similar to the CMI response to HIV infection, peptide-specific T cell recognition patterns changed over time. Early post infection (1 month), immune responses were directed to the peptides in the carboxyl-terminus variable region. By six months post infection, the peptide recognition spanned the entire gp90 sequence. These results indicate that peptide recognition broadens during EIAV infection.
authors.affiliation: Department of Veterinary Science, University of Kentucky, Lexington, KY, USA.
authors.forename: Chong
authors.initials: C
authors.lastname: Liu
authors.affiliation: Department of Veterinary Science, University of Kentucky, Lexington, KY, USA.
authors.forename: Sheila J
authors.initials: SJ
authors.lastname: Cook
authors.affiliation: Center for Vaccine Research and Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Jodi K
authors.initials: JK
authors.lastname: Craigo
authors.affiliation: Department of Veterinary Science, University of Kentucky, Lexington, KY, USA.
authors.forename: Frank R
authors.initials: FR
authors.lastname: Cook
authors.affiliation: Department of Veterinary Science, University of Kentucky, Lexington, KY, USA.
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Issel
authors.affiliation: Center for Vaccine Research and Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Ronald C
authors.initials: RC
authors.lastname: Montelaro
authors.affiliation: Department of Veterinary Science, University of Kentucky, Lexington, KY, USA. Electronic address: David.Horohov@uky.edu.
authors.forename: David W
authors.initials: DW
authors.lastname: Horohov
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D000915:Antibody Affinity; D000939:Epitopes; D004859:Equine Infectious Anemia / Q000276:immunology* / Q000378:metabolism; D015967:Gene Expression Regulation, Viral / Q000276:immunology; D014644:Genetic Variation; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism*; D006736:Horses; D007111:Immunity, Cellular / Q000502:physiology*; D004860:Infectious Anemia Virus, Equine / Q000235:genetics / Q000378:metabolism*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D000914:Antibodies, Viral; D000939:Epitopes; D006023:Glycoproteins; D014764:Viral Proteins
keywords: Cellular immune responses; EIAV; Envelope; Immunodominant shifting; Lentivirus