Fig. 4.

RICE recognition behavior. (A and B) Probabilities for a single selected TCR to recognize (A) random peptides and (B) point mutants of self-peptides for the analytically tractable limits and for higher values of $N_n$. In both cases, the effect of increasing the number of negatively selecting self-peptides to $N_n={\mathrm{\hspace{0.17em}10}}^4$ has a relatively small effect on recognition rates in the range of relevant values ($11$–$13$) of $E_n$. The simulation averaged over all of the surviving TCRs from the initial cohort of ${10}^5$, a lower estimate of the mouse T cell diversity for a single MHC (36); ${10}^4$ random and point-mutant variants were tested. (C) The total recognition probability for the surviving ($5\times {\mathrm{\hspace{0.17em}10}}^4$) TCR cohort to recognize: a random peptide (black curve) and a single-site mutant of a native peptide (red). (D) The ratio of the two recognition probabilities in C; ${10}^4$ peptides of each class were tested. Included in D is the theoretical estimate of the ratio $(1-{(1-{\stackrel{\sim }{p}}_1)}^{N_s})/(1-{(1-{\widehat{p}}_0)}^{N_s})$, where $N_s(E_n)$ is the number of TCRs that survived selection.