title: Ex-vivo recognition of late-lytic CD8 epitopes specific for Kaposi's sarcoma-associated herpesvirus (KSHV) by HIV/KSHV-coinfected individuals.
abstract: Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiological agent of Kaposi's sarcoma (KS), the most common cancer in individuals with untreated HIV/AIDS. Host control of KSHV infection and KS oncogenesis by CD8 T cells remains underexplored. Although KSHV CD8 epitopes have been identified, the responses they elicit are weak and little is known about their relative importance. We sought to make a direct comparison of the recognition of a selection of the best-described known epitopes by a cohort of KSHV-seropositive, HIV-co-infected individuals, in order to assess the relative dominance of these epitopes. We further sought to identify novel epitopes from within a candidate immunogenic protein encoded by KSHV ORF28. MHC binding and denaturation assays identified putative novel A*0201-restricted epitopes from within the late-lytic glycoprotein ORF28. Recognition of these candidate epitopes was tested in a cohort of KSHV-seropositive, HIV-1-seropositive, A*0201-positive individuals by ex vivo ELISPOT, and compared with recognition of nine previously described epitopes. One novel late-lytic epitope from ORF28 was recognized by 7.1% of individuals, and was used for further investigation of KSHV-specific T cells using multimer technology. One known late-lytic epitope from the glycoprotein-encoding K8.1 was recognized by 71.4% of individuals, and represented an immunodominant KSHV epitope, but was too hydrophobic for multimer synthesis. This study identifies two KSHV CD8 epitopes derived from late-lytic antigens that are recognized by KSHV-seropositive, HIV co-infected individuals, and will be useful in future immunological studies into the CD8 response against KSHV in similar patient cohorts.
authors.affiliation: Department of Immunology, Imperial College London, London, UK.
authors.forename: Rebecca C
authors.initials: RC
authors.lastname: Robey
authors.forename: Salvinia
authors.initials: S
authors.lastname: Mletzko
authors.forename: Mark
authors.initials: M
authors.lastname: Bower
authors.forename: Rhonda
authors.initials: R
authors.lastname: Meys
authors.forename: Marta
authors.initials: M
authors.lastname: Boffito
authors.forename: Mark
authors.initials: M
authors.lastname: Nelson
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Bunker
authors.forename: Frances M
authors.initials: FM
authors.lastname: Gotch
mesh_terms: D000328:Adult; D000956:Antigens, Viral / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D058501:Enzyme-Linked Immunospot Assay; D018604:Epitope Mapping; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D015658:HIV Infections / Q000150:complications* / Q000276:immunology; D019288:Herpesvirus 8, Human / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012514:Sarcoma, Kaposi / Q000276:immunology* / Q000821:virology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
chemical_list: D000956:Antigens, Viral; D018984:Epitopes, T-Lymphocyte