title: Proteasomes generate spliced epitopes by two different mechanisms and as efficiently as non-spliced epitopes.
abstract: Proteasome-catalyzed peptide splicing represents an additional catalytic activity of proteasomes contributing to the pool of MHC-class I-presented epitopes. We here biochemically and functionally characterized a new melanoma gp100 derived spliced epitope. We demonstrate that the gp100(mel)47-52/40-42 antigenic peptide is generated in vitro and in cellulo by a not yet described proteasomal condensation reaction. gp100(mel)47-52/40-42 generation is enhanced in the presence of the β5i/LMP7 proteasome-subunit and elicits a peptide-specific CD8(+) T cell response. Importantly, we demonstrate that different gp100(mel)-derived spliced epitopes are generated and presented to CD8(+) T cells with efficacies comparable to non-spliced canonical tumor epitopes and that gp100(mel)-derived spliced epitopes trigger activation of CD8(+) T cells found in peripheral blood of half of the melanoma patients tested. Our data suggest that both transpeptidation and condensation reactions contribute to the frequent generation of spliced epitopes also in vivo and that their immune relevance may be comparable to non-spliced epitopes.
authors.affiliation: Institut für Biochemie, Charité-Universitätsmedizin Berlin, Charitéplatz 1, D-10117 Berlin, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Ebstein
authors.affiliation: Institut für Biochemie, Charité-Universitätsmedizin Berlin, Charitéplatz 1, D-10117 Berlin, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Textoris-Taube
authors.affiliation: Institut für Biochemie, Charité-Universitätsmedizin Berlin, Charitéplatz 1, D-10117 Berlin, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Keller
authors.affiliation: Institut für Biochemie, Charité-Universitätsmedizin Berlin, Charitéplatz 1, D-10117 Berlin, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Golnik
authors.affiliation: Ludwig Institute for Cancer Research, WELBIO (Walloon Excellence in Life Sciences and Biotechnology) and the de Duve Institute, Université catholique de Louvain, Place de l'Université 1, B-1200 Brussels, Belgium.
authors.forename: N
authors.initials: N
authors.lastname: Vigneron
authors.affiliation: Ludwig Institute for Cancer Research, WELBIO (Walloon Excellence in Life Sciences and Biotechnology) and the de Duve Institute, Université catholique de Louvain, Place de l'Université 1, B-1200 Brussels, Belgium.
authors.forename: B J
authors.initials: BJ
authors.lastname: Van den Eynde
authors.affiliation: Department of Dermatology, Universitätsklinikum Erlangen, Ulmenweg 18, D-91052 Erlangen, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Schuler-Thurner
authors.affiliation: Klinik für Dermatologie, Venerologie und Allergologie, Universitätsklinikum Essen D - 45122 Essen, Germany &German Cancer Consortium (DKTK), Hufelandstraße 55, D-69120 Heidelberg, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Schadendorf
authors.affiliation: Max-Delbrück-Center for Molecular Medicine, Robert-Rössle-Str. 10, D-13092 Berlin, Germany.
authors.forename: F K M
authors.initials: FK
authors.lastname: Lorenz
authors.affiliation: Max-Delbrück-Center for Molecular Medicine, Robert-Rössle-Str. 10, D-13092 Berlin, Germany.|Institute of Biology, Humboldt University Berlin, Charitéplatz 1, D-10115 Berlin, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Uckert
authors.affiliation: Institut für Biochemie, Charité-Universitätsmedizin Berlin, Charitéplatz 1, D-10117 Berlin, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Urban
authors.affiliation: Institut für Biochemie, Charité-Universitätsmedizin Berlin, Charitéplatz 1, D-10117 Berlin, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Lehmann
authors.affiliation: Institut für Biochemie, Charité-Universitätsmedizin Berlin, Charitéplatz 1, D-10117 Berlin, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Albrecht-Koepke
authors.affiliation: Institut für Biochemie, Charité-Universitätsmedizin Berlin, Charitéplatz 1, D-10117 Berlin, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Janek
authors.affiliation: Institut für Biochemie, Charité-Universitätsmedizin Berlin, Charitéplatz 1, D-10117 Berlin, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Henklein
authors.affiliation: Institut für Biochemie, Charité-Universitätsmedizin Berlin, Charitéplatz 1, D-10117 Berlin, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Niewienda
authors.affiliation: Institut für Biochemie, Charité-Universitätsmedizin Berlin, Charitéplatz 1, D-10117 Berlin, Germany.
authors.forename: P M
authors.initials: PM
authors.lastname: Kloetzel
authors.affiliation: Institut für Biochemie, Charité-Universitätsmedizin Berlin, Charitéplatz 1, D-10117 Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Mishto
mesh_terms: D000465:Algorithms; D017398:Alternative Splicing; D017951:Antigen Presentation / Q000276:immunology; D000941:Antigens / Q000737:chemistry; D000951:Antigens, Neoplasm / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology; D016022:Case-Control Studies; D002384:Catalysis; D045744:Cell Line, Tumor; D000939:Epitopes / Q000737:chemistry*; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D006367:HeLa Cells; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D008544:Melanocytes / Q000166:cytology; D008545:Melanoma / Q000378:metabolism; D010455:Peptides / Q000737:chemistry; D011336:Probability; D046988:Proteasome Endopeptidase Complex / Q000737:chemistry / Q000378:metabolism*; D058951:gp100 Melanoma Antigen / Q000737:chemistry*
chemical_list: D000941:Antigens; D000951:Antigens, Neoplasm; D000939:Epitopes; D018984:Epitopes, T-Lymphocyte; D010455:Peptides; D058951:gp100 Melanoma Antigen; D007371:Interferon-gamma; D046988:Proteasome Endopeptidase Complex