title: Identification of potential HLA class I and class II epitope precursors associated with heat shock protein 70 (HSPA).
abstract: Heat shock protein 70 (HSPA) is a molecular chaperone which has been suggested to shuttle human leukocyte antigen (HLA) epitope precursors from the proteasome to the transporter associated with antigen processing. Despite the reported observations that peptides chaperoned by HSPA are an effective source of antigens for cross-priming, little is known about the peptides involved in the process. In this study, we investigated the possible involvement of HSPA in HLA class I or class II antigen presentation and analysed the antigenic potential of the associated peptides. HSPA was purified from CCRF-CEM and K562 cell lines, and using mass spectrometry techniques, we identified 44 different peptides which were co-purified with HSPA. The affinity of the identified peptides to two HSPA isoforms, HSPA1A and HSPA8, was confirmed using a peptide array. Four of the HSPA-associated peptides were matched with 13 previously reported HLA epitopes. Of these 13 peptides, nine were HLA class I and four were HLA class II epitopes. These results demonstrate the association of HSPA with HLA class I and class II epitopes, therefore providing further evidence for the involvement of HSPA in the antigen presentation process.
authors.affiliation: Haematological Sciences, Institute of Cellular Medicine, Medical School, Framlington Place, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Pawel
authors.initials: P
authors.lastname: Stocki
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Morris
authors.forename: Christian
authors.initials: C
authors.lastname: Preisinger
authors.forename: Xiao N
authors.initials: XN
authors.lastname: Wang
authors.forename: Walter
authors.initials: W
authors.lastname: Kolch
authors.forename: Gabriele
authors.initials: G
authors.lastname: Multhoff
authors.forename: Anne M
authors.initials: AM
authors.lastname: Dickinson
mesh_terms: D015153:Blotting, Western; D045744:Cell Line, Tumor; D002851:Chromatography, High Pressure Liquid; D000939:Epitopes / Q000737:chemistry* / Q000378:metabolism*; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D015395:Histocompatibility Antigens Class I / Q000737:chemistry* / Q000378:metabolism*; D000949:Histocompatibility Antigens Class II / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D013058:Mass Spectrometry
chemical_list: D000939:Epitopes; D018840:HSP70 Heat-Shock Proteins; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II