Figure 1.

Relationships among T-cell activity, T-cell receptor (TCR) equilibrium binding constants, and TCR dissociation kinetics. (a) Equilibrium binding constants K_D (affinity) and half-life (t_1/2) measurements for wild-type TCRs were plotted using published values shown in Table 1. Theoretical receptor (X) represents the binding parameters of a TCR that, if available, would provide additional insight into the mechanisms of T-cell activation as described in the text. (b) Equilibrium binding constants K_D (affinity) and half-life (t_1/2) measurements for TCRs engineered for high affinity, from published values shown in Table 2, were added to the data in (a). The type of T-cell activity (agonist, weak agonist, antagonist) mediated by each TCR is indicated by the symbols.