Low affinity interaction of peptide-MHC complexes with T cell receptors.
The interaction of antigen-specific T cell receptors (TCRs) with their ligands, peptides bound to molecules of the major histocompatibility complex (MHC), is central to most immune responses, yet little is known about its chemical characteristics. The binding to T cells of a labeled monoclonal antibody to the TCR was inhibited by soluble class II MHC heterodimers complexed to different peptides. Inhibition was both peptide- and TCR-specific and of low affinity, with a KD = 4 x 10(-5) to 6 x 10(-5) M, orders of magnitude weaker than comparable antibody-antigen interactions. This finding is consistent with the scanning nature of T cell recognition and suggests that antigen-independent adhesion precedes TCR engagement.
Matsui
K
K
Howard Hughes Medical Institute, Stanford, CA.
Boniface
J J
JJ
Reay
P A
PA
Schild
H
H
Fazekas de St Groth
B
B
Davis
M M
MM
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D000938:Antigen-Presenting Cells / Q000276:immunology; D002460:Cell Line; D014644:Genetic Variation; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D007700:Kinetics; D046911:Macromolecular Substances; D008285:Major Histocompatibility Complex; D008954:Models, Biological; D008969:Molecular Sequence Data; D010455:Peptides / Q000276:immunology / Q000378:metabolism*; D011485:Protein Binding; D011948:Receptors, Antigen, T-Cell / Q000276:immunology / Q000502:physiology*; D013601:T-Lymphocytes / Q000276:immunology
D000911:Antibodies, Monoclonal; D007140:Immunoglobulin Fab Fragments; D046911:Macromolecular Substances; D010455:Peptides; D011948:Receptors, Antigen, T-Cell