title: Identification of an HLA-A*0201-restricted T-cell epitope on the MPT51 protein, a major secreted protein derived from Mycobacterium tuberculosis, by MPT51 overlapping peptide screening.
abstract: CD8+ T cells play a pivotal role in protection against Mycobacterium tuberculosis infection. We identified a novel HLA-A*0201-restricted CD8+ T-cell epitope on a dominant secreted antigen of M. tuberculosis, MPT51, in HLA-A*0201 transgenic HHD mice. HHD mice were immunized with plasmid DNA encoding MPT51 with gene gun bombardment, and gamma interferon (IFN-gamma) production by the immune splenocytes was analyzed. In response to overlapping synthetic peptides covering the mature MPT51 sequence, the splenocytes were stimulated to produce IFN-gamma by only one peptide, p51-70. Three-color flow cytometric analysis of intracellular IFN-gamma and cell surface CD4 and CD8 staining revealed that the MPT51 p51-70 peptide contains an immunodominant CD8+ T-cell epitope. Further analysis using computer algorithms permitted identification of a bona fide T-cell epitope, p53-62. A major histocompatibility complex class I stabilization assay using T2 cells confirmed that this epitope binds to HLA-A*0201. The T cells were capable of lysing MPT51 p53-62 peptide-pulsed T2 cells. In addition, MPT51 p53-62-specific memory CD8+ T cells were found in tuberculin skin test-positive HLA-A*0201+ healthy individuals. Use of this HLA-A*0201-restricted CD8+ T-cell epitope for analysis of the role of MPT51-specific T cells in M. tuberculosis infection and for design of vaccines against tuberculosis is feasible.
authors.affiliation: Department of Infectious Diseases, Hamamatsu University School of Medicine, 1-20-1 Handa-yama, Higashi-ku, Hamamatsu 431-3192, Japan.
authors.forename: Taiki
authors.initials: T
authors.lastname: Aoshi
authors.forename: Toshi
authors.initials: T
authors.lastname: Nagata
authors.forename: Mina
authors.initials: M
authors.lastname: Suzuki
authors.forename: Masato
authors.initials: M
authors.lastname: Uchijima
authors.forename: Dai
authors.initials: D
authors.lastname: Hashimoto
authors.forename: Alireza
authors.initials: A
authors.lastname: Rafiei
authors.forename: Takafumi
authors.initials: T
authors.lastname: Suda
authors.forename: Kingo
authors.initials: K
authors.lastname: Chida
authors.forename: Yukio
authors.initials: Y
authors.lastname: Koide
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology* / Q000378:metabolism*; D001500:BCG Vaccine / Q000276:immunology; D001426:Bacterial Proteins / Q000276:immunology* / Q000378:metabolism*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002460:Cell Line; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D015234:HLA-A Antigens / Q000276:immunology* / Q000378:metabolism; D015789:HLA-A2 Antigen; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D019151:Peptide Library; D013154:Spleen / Q000166:cytology; D014376:Tuberculosis / Q000276:immunology
chemical_list: D000942:Antigens, Bacterial; D001500:BCG Vaccine; D001426:Bacterial Proteins; D018984:Epitopes, T-Lymphocyte; D015234:HLA-A Antigens; C435939:HLA-A*02:01 antigen; D015789:HLA-A2 Antigen; C082911:MPT51 protein, Mycobacterium; D019151:Peptide Library; D007371:Interferon-gamma