title: Antigen recognition properties of a Vgamma1.3Vdelta2-T-cell receptor from a rare variant of polymyositis.
abstract: Previously we partially characterized an autoreactive human Vgamma1.3Vdelta2-T-cell receptor (TCR) that had originally been identified in muscle of a patient with an unusual form of polymyositis. This TCR recognizes a muscle-associated auto-antigen in a CDR3-dependent, MHC non-restricted way. Here we show that this TCR also recognizes an antigen from Escherichia coli. Like the muscle-associated mammalian antigen, the bacterial antigen is recognized in a CDR3-dependent, but MHC-non-restricted way. Both antigens have strikingly similar molecular characteristics suggesting that their epitopes are at least very similar. The dissociation kinetics of the bacterial antigen-TCR complexes was investigated by surface plasmon resonance using soluble single-chain TCR molecules produced in COS-7 cells. The measured dissociation rate constant (k(off)=5.7 x 10(-3) s(-1)) shows that the complexes dissociate more slowly than most previously described antigen/alphabeta-TCR complexes, but much faster than antibody/antigen pairs. These results (a) provide further insight into the molecular properties of this unusual TCR, and (b) should help in future attempts to identify the elusive target antigen(s).
authors.affiliation: Max-Planck-Institute of Neurobiology, Am Klopferspitz 18a, D-82152 Martinsried, Germany. dornmair@neuro.mpg.de
authors.forename: Klaus
authors.initials: K
authors.lastname: Dornmair
authors.forename: Christian K
authors.initials: CK
authors.lastname: Schneider
authors.forename: Joachim
authors.initials: J
authors.lastname: Malotka
authors.forename: Georg
authors.initials: G
authors.lastname: Dechant
authors.forename: Heinz
authors.initials: H
authors.lastname: Wiendl
authors.forename: Reinhard
authors.initials: R
authors.lastname: Hohlfeld
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology*; D015551:Autoimmunity / Q000276:immunology*; D002478:Cells, Cultured; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D004926:Escherichia coli / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D017285:Polymyositis / Q000276:immunology*; D011485:Protein Binding; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism; D020349:Surface Plasmon Resonance
chemical_list: D000942:Antigens, Bacterial; D018984:Epitopes, T-Lymphocyte; D016692:Receptors, Antigen, T-Cell, gamma-delta