Fig. 9

Analog amplifier model for the mechanism of coagonism. Nonstimulatory pMHC molecules recruit CD8-Lck into the immunological synapse. Preconcentrated Lck further phosphorylate the ITAMs of TCR-CD3ζ which are engaged with specific antigenic pMHC. Enhanced pCD3ζ provide more docking sites for Zap70 to be phosphorylated. Enhanced pZap70 signal amplifies the downstream TCR signaling pathway including the phosphorylation of Erk. pErk translocates into the nucleus and enhances the effector functional readouts of T-cell activation