Antigen recognition properties of a Vgamma1.3Vdelta2-T-cell receptor from a rare variant of polymyositis.
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).
Dornmair
Klaus
K
Max-Planck-Institute of Neurobiology, Am Klopferspitz 18a, D-82152 Martinsried, Germany. dornmair@neuro.mpg.de
Schneider
Christian K
CK
Malotka
Joachim
J
Dechant
Georg
G
Wiendl
Heinz
H
Hohlfeld
Reinhard
R
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
D000942:Antigens, Bacterial; D018984:Epitopes, T-Lymphocyte; D016692:Receptors, Antigen, T-Cell, gamma-delta