A Peptide from Heat Shock Protein 60 Is the Dominant Peptide Bound To Qa-1 in the Absence of the MHC Class Ia Leader Sequence Peptide Qdm

• Published in: The Journal of immunology (1950) 2003-05, Vol.170 (10), p.5027-5033
• Main Authors: Davies, Adrian, Kalb, Suzanne, Liang, Bitao, Aldrich, Carla J, Lemonnier, Francois A, Jiang, Hong, Cotter, Robert, Soloski, Mark J
• Format: Article
• Language: English
• Subjects: Animals; Antigen Presentation; Cell Line; Chaperonin 60 - immunology; Chaperonin 60 - metabolism; Clone Cells; Cytotoxicity, Immunologic; Epitopes, T-Lymphocyte - metabolism; Histocompatibility Antigens Class I - metabolism; Immunodominant Epitopes - metabolism; Mice; Mice, Inbred C57BL; Mice, Knockout; Oligopeptides - immunology; Oligopeptides - metabolism; Peptide Fragments - immunology; Peptide Fragments - metabolism; Peptides - immunology; Peptides - metabolism; Protein Binding - immunology; Protein Sorting Signals; T-Lymphocytes, Cytotoxic - immunology; T-Lymphocytes, Cytotoxic - metabolism
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.170.10.5027

The MHC class Ib molecule Qa-1 binds specifically and predominantly to a single 9-aa peptide (AMAPRTLLL) derived from the leader sequence of many MHC class Ia proteins. This peptide is referred to as Qdm. In this study, we report the isolation and sequencing of a heat shock protein 60-derived peptide (GMKFDRGYI) from Qa-1. This peptide is the dominant peptide bound to Qa-1 in the absence of Qdm. A Qa-1-restricted CTL clone recognizes this heat shock protein 60 peptide, further verifying that it binds to Qa-1 and a peptide from the homologous Salmonella typhimurium protein GroEL (GMQFDRGYL). These observations have implications for how Qa-1 can influence NK cell and T cell effector function via the TCR and CD94/NKG2 family members, and how this effect can change under conditions that cause the peptides bound to Qa-1 to change.