Kinetics of T-cell receptor binding to peptide/I-Ek complexes: correlation of the dissociation rate with T-cell responsiveness.
AUTOR(ES)
Matsui, K
RESUMO
Recognition by T-cell antigen receptors (TCRs) of processed peptides bound to major histocompatibility complex (MHC) molecules is required for the initiation of most T-lymphocyte responses. Despite the availability of soluble forms of TCRs and MHC heterodimers, this interaction has proven difficult to study directly due to the very low affinity. We report here on the kinetics of TCR binding to peptide/MHC complexes in a cell-free system using surface plasmon resonance. The apparent association rates for the interactions of related peptide/MHC complexes to one such TCR are relatively slow (900-3000 M-1.s-1) and dissociation rates are very fast (0.3-0.06 s-1) with t1/2 of 2-12 s at 25 degrees C. The calculated affinity of the engineered soluble molecules compares well with previously reported competition data for native TCRs or competition data reported here for native peptide/MHC complexes, indicating that these soluble heterodimers bind in the same manner as the original molecules expressed on cells. We also find that the peptide variants which give weaker T-cell stimulatory responses have similar affinities but distinctly faster dissociation rates compared with the original peptide (when loaded onto the MHC molecule) and that this later property may be responsible for their lower activity. This has implications for both downstream signaling events and models of TCR-peptide antagonists.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=45540Documentos Relacionados
- Antibodies to synthetic joining segment peptide of the T-cell receptor beta-chain: serological cross-reaction between products of T-cell receptor genes, antigen binding T-cell receptors, and immunoglobulins.
- Passive immunotherapy for retroviral disease: influence of major histocompatibility complex type and T-cell responsiveness.
- Coaggregation of the T-cell receptor with CD4 and other T-cell surface molecules enhances T-cell activation.
- In Vivo Selection of T-Cell Receptor Junctional Region Sequences by HLA-A2 Human T-Cell Lymphotropic Virus Type 1 Tax11-19 Peptide Complexes
- T-cell receptor genes in autoimmune mice: T-cell subsets have unexpected T-cell receptor gene programs.