Fig. 5.
Self/nonself discrimination. (A) Probability distribution of close-contact residence times for TCRs in the presence and absence of agonist and self pMHC, for a close contact of radius r0 = 220 nm, showing that discrimination of ligands is not dependent on a threshold value for tmin. (B) Probability that at least one TCR will be triggered, i.e., stay in the contact for tmin ≥ 2 s, as a function of contact duration tf in the presence and absence of agonist pMHC with a low koff (koff = 1 s−1, 30 pMHC/μm2), or a self pMHC with a larger koff present at higher pMHC densities (koff = 50 s−1, 300 pMHC/μm2); r0 = 220 nm. (C) Comparison of the triggering probability in the absence of pMHC for close contacts of 220 and 440 nm. (D) Triggering probability as a function of pMHC densities and pMHC off rates for a single contact of 220 nm radius with a duration of tf = 120 s. (E) Triggering probability as a function of close contact radius for pMHC with varying off rates for a contact duration of tf = 120 s. (F) Contribution to the overall signal of TCRs that are triggered without binding to pMHC, in the presence of agonist pMHC with varying koff (30 pMHC/μm2).