title: Identification of a naturally processed cyclin D1 T-helper epitope by a novel combination of HLA class II targeting and differential mass spectrometry.
abstract: T-helper (Th) cells play an important role in orchestrating the effector function of CTL in anti-tumor immunity. However, only a limited number of Th cell epitopes has been characterized. Here we describe a novel approach for identifying naturally processed and presented peptides derived from chosen antigens. This method combines a transfection step of antigen-presenting cells with a vector encoding a fusion protein between the Ii chain and the antigen of interest, elution of the HLA-bound peptides and identification of the antigen-derived peptides by mass spectrometric comparison to the non-transfected cells. In vitro-stimulated Th cells against the identified peptide of interest specifically recognize transfectants overexpressing the cognate antigen. Using this approach, we were able to identify the HLA-DR4-restricted Th cell epitope NPPSMVAAGSVVAAV derived from cyclin D1, which is frequently overexpressed in tumors. This method will help in identifying peptide candidates for vaccination studies for tumor immunotherapy.
authors.affiliation: Department of Immunology, Institute for Cell Biology, University of Tübingen, Tübingen, Germany.
authors.forename: Jörn
authors.initials: J
authors.lastname: Dengjel
authors.forename: Patrice
authors.initials: P
authors.lastname: Decker
authors.forename: Oliver
authors.initials: O
authors.lastname: Schoor
authors.forename: Florian
authors.initials: F
authors.lastname: Altenberend
authors.forename: Toni
authors.initials: T
authors.lastname: Weinschenk
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Rammensee
authors.forename: Stefan
authors.initials: S
authors.lastname: Stevanovic
mesh_terms: D019938:Cyclin D1 / Q000276:immunology*; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006801:Humans; D013058:Mass Spectrometry; D010446:Peptide Fragments / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
chemical_list: D018984:Epitopes, T-Lymphocyte; D000949:Histocompatibility Antigens Class II; D010446:Peptide Fragments; D019938:Cyclin D1