A SIMPLE MATHEMATICAL-MODEL FOR THE FUNCTIONAL PEPTIDE MHC/TCR INTERACTIONS/

T cell-specific activation requires ligation of TCRs with peptide-MHC complexes on the APC. On the basis of simple chemical and statistical laws, we have constructed a mathematical model to describe this trimol ecular interaction between effector and target cells, and we demonstra te its predictive value in the case of in vitro peptide Ag titration. Moreover, this model can generate mechanistic explanations for cellula r immunity phenomena like anergy, peripheral tolerance, cell-mediated suppression, TCR antagonism, and thymic selection events.