title: HLA class I binding promiscuity of the CD8 T-cell epitopes of human papillomavirus type 16 E6 protein.
abstract: One of the critical steps in the progression to cervical cancer appears to be the establishment of persistent human papillomavirus (HPV) infection. We have demonstrated that the lack of cytotoxic T-lymphocyte response to HPV type 16 (HPV 16) E6 protein was associated with persistence and that the potential presence of dominant CD8 T-cell epitopes was most frequently found (n = 4 of 23) in the E6 16-40 region by examining the pattern of CD8 T-cell epitopes within the E6 protein in women who had cleared their HPV 16 infections. The goal of this study was to define the minimal/optimal amino acid sequences and the HLA restricting molecules of these dominant CD8 T-cell epitopes as well as those of subdominant ones if present. Three dominant epitopes, E6 29-38 (TIHDIILECV; restricted by the HLA-A0201 molecule), E6 29-37 (TIHDIILEC; restricted by B48), and E6 31-38 (HDIILECV; restricted by B4002), and one subdominant epitope, E6 52-61 (FAFRDLCIVY; restricted by B35) were characterized. Taken together with a previously described dominant epitope, E6 52-61 (FAFRDLCIVY; restricted by B57), the CD8 T-cell epitopes demonstrated striking HLA class I binding promiscuity. All of these epitopes were endogenously processed, but the presence of only two of the five epitopes could have been predicted based on the known binding motifs. The HLA class I promiscuity which has been described for human immunodeficiency virus may be more common than previously recognized.
authors.affiliation: Department of Dermatology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA. mnakagawa@uams.edu
authors.forename: Mayumi
authors.initials: M
authors.lastname: Nakagawa
authors.forename: Kevin H
authors.initials: KH
authors.lastname: Kim
authors.forename: Tiffany M
authors.initials: TM
authors.lastname: Gillam
authors.forename: Anna-Barbara
authors.initials: AB
authors.lastname: Moscicki
mesh_terms: D001667:Binding, Competitive; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D045744:Cell Line, Tumor; D018984:Epitopes, T-Lymphocyte / Q000737:chemistry / Q000378:metabolism*; D005805:Genes, MHC Class I; D006680:HLA Antigens / Q000378:metabolism*; D006801:Humans; D009856:Oncogene Proteins, Viral / Q000276:immunology*; D027383:Papillomaviridae / Q000276:immunology*; D030361:Papillomavirus Infections / Q000276:immunology*; D012097:Repressor Proteins / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology
chemical_list: C068651:E6 protein, Human papillomavirus type 16; D018984:Epitopes, T-Lymphocyte; D006680:HLA Antigens; D009856:Oncogene Proteins, Viral; D012097:Repressor Proteins