Effect of local anaesthetics on human natural killer cell activity

We explored the effects of local anaesthetics, which are proposed to affect the plasma membrane, on human natural killer (NK) cells. Human NK cell activity was inhibited by lidocaine and procaine in a dose-dependent manner. Procaine inhibited not only NK cytolysis but also the binding of NK cells to target cells when NK cells were pre-incubated with procaine, whereas procaine inhibited NK cytolysis without interfering with the binding when it was added after the binding was completed. These findings suggest that local anaesthetics may inhibit not only the recognition process but also the post-recognition process of human NK cells.