Fig. 4: Mechano-regulated structural mechanism of CD8 enhancement for moderate or ultra-strong TCR–pMHC binding.
From: TCR catch bonds nonlinearly control CD8 cooperation to shape T cell specificity
a, b Sequential snapshots of cv-SMD simulations illustrating the dissociation of R4-MHC from 2C-TCR–CD8αβ (a) or m67-TCR–CD8αβ (b) modeled structural complexes under mechanical force pulling. c, d Force-induced angle changes of the TCR–pMHC (c) and the CD8β–pMHC interface (d) within 2C- and m67-TCRs systems in cv-SMD simulations. Detailed definitions of these angles are described in Supplementary information Fig. S6. e–g Structural footprint of CD8β (yellow) in complex with R4-MHC (purple) for 2C- (f) or m67-TCRs (g) systems, as depicted in two representative snapshots corresponding to states I1 and I2. Contact area between CD8β (or its Ile2 residue) and MHC under mechanical force in cv-SMD simulations for the 2C-TCR–R4-MHC–CD8 (h) and the m67-TCR–R4-MHC–CD8 (i) complexes. Error bars are ± SEMs. All statistical analyses were conducted using unpaired student's t-tests. Statistical significance was indicated as follows: ns not significant, *P < 0.05, **P < 0.01, ****P < 0.0001.
