λと免疫
T-cell recognition is often described in biochemical terms, but its structural logic is surprisingly simple.
Our λ‑analysis quantifies how much “freedom to move” a protein complex retains.
A higher λ means the structure can still breathe; a lower λ indicates that the complex has become tightly constrained.
When we applied this method to an HLA-A2 molecule presenting a viral peptide (PDB 1AO7),
the complex showed a moderate degree of structural freedom (λ = 0.4667).
However, once a T-cell receptor bound to the same antigenic surface (PDB 2VLR),
the system collapsed into a highly constrained state (λ = 0.02533).
This dramatic ~20‑fold reduction in λ illustrates a fundamental principle of immune signaling:
TCR binding does not simply “turn on” a receptor — it mechanically restricts the antigen-presenting platform.
Only when additional, biologically meaningful stimuli are present can such a constrained complex cross the signaling threshold.
By quantifying these structural transitions, λ-analysis provides a new way to visualize
how T cells discriminate between harmless and dangerous cues —
not by affinity alone, but by the freedom or restriction encoded in the molecular assembly itself.
2026年3月15日 | カテゴリー：論文/講義/発表用, Cohors Irregularis |
