Structural analysis of two HLA-DR-presented autoantigenic epitopes: crucial role of peripheral but not central peptide residues for T-cell receptor recognition
Φόρτωση...
Ημερομηνία
Συγγραφείς
De Oliveira, D. B.
Harfouch-Hammoud, E.
Otto, H.
Papandreou, N. A.
Stern, L. J.
Cohen, H.
Boehm, B. O.
Bach, J.
Caillat-Zucman, S.
Walk, T.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer-reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
Mol Immunol
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
Specific and major histocompatibility complex (MHC)-restricted T-cell recognition of antigenic peptides is based on interactions of the T-cell receptor (TCR) with the MHC alpha helices and solvent exposed peptide residues termed TCR contacts. In the case of MHC class II-presented peptides, the latter are located in the positions p2/3, p5 and p7/8 between MHC anchor residues. For numerous epitopes, peptide substitution studies have identified the central residue p5 as primary TCR contact characterized by very low permissiveness for peptide substitution, while the more peripheral positions generally represent auxiliary TCR contacts. In structural studies of TCR/peptide/MHC complexes, this has been shown to be due to intimate contact between the TCR complementarity determining region (CDR) three loops and the central peptide residue. We asked whether this model also applied to two HLA-DR presented epitopes derived from an antigen targeted in type 1 diabetes. Large panels of epitope variants with mainly conservative single substitutions were tested for human leukocyte antigen (HLA) class II binding affinity and T cell stimulation. Both epitopes bind with high affinity to the presenting HLA-DR molecules. However, in striking contrast to the standard distribution of TCR contacts, recognition of the central p5 residue displayed high permissiveness even for non-conservative substitutions, while the more peripheral p2 and p8 TCR contacts showed very low permissiveness for substitution. This suggests that intimate TCR interaction with the central peptide residue is not always required for specific antigen recognition and can be compensated by interactions with positions normally acting as auxiliary contacts.
Περιγραφή
Λέξεις-κλειδιά
*Antigen Presentation, Autoantigens/*chemistry, Complementarity Determining Regions, Diabetes Mellitus, Type 1/*immunology, Epitopes, HLA-DR Antigens/*chemistry/immunology, Lymphocyte Activation, Models, Structural, Peptide Fragments/*immunology, Receptors, Antigen, T-Cell/*chemistry/immunology, T-Lymphocytes/immunology
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
http://www.ncbi.nlm.nih.gov/pubmed/11257303
http://ac.els-cdn.com/S0161589000001097/1-s2.0-S0161589000001097-main.pdf?_tid=08f9c14243e59d301354c18cf08549e7&acdnat=1334126665_32dd9e3b7370bfb1930fade5402a180e
http://ac.els-cdn.com/S0161589000001097/1-s2.0-S0161589000001097-main.pdf?_tid=08f9c14243e59d301354c18cf08549e7&acdnat=1334126665_32dd9e3b7370bfb1930fade5402a180e
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Επιστημών Υγείας. Τμήμα Ιατρικής