Figure 2.

Immunotyrosine-based inhibitory motif-receptor signaling induces a reverse stop signal. IL-2-cultured primary human NK cells were labeled with the membrane dye PKH26 and imaged by TIRF microscopy on supported lipid bilayers containing activating and inhibitory NK receptor ligands. (A,B) Representative trajectories for KIR2DL3⁺ or NKG2A⁺ NK cells on bilayers containing either activating ligands alone (A) or mixtures of activating and inhibitory ligands (B). Blue trajectories denote average speed ≥30 nm/s, while red trajectories denote average speed <30 nm/s. (C) Average speed of KIR2DL3⁺ or NKG2A⁺ NK cells on bilayers containing the indicated activating and inhibitory ligands (n ≥ 28 cells per condition). Factors relating average speed in the presence or absence of inhibitory ligand for each activating condition are shown in blue. Magenta lines and error bars indicate mean and SEM. P-values were calculated using the Mann–Whitney test.