Valinomycin-induced apoptosis of human NK cells is predominantly caspase independent.

Human NK cells are sensitive to the exogenous toxic compound valinomycin. This toxin, produced by Streptomyces griseus in moisture damaged buildings, induces apoptosis by dissipating the membrane potential in mitochondria. In this paper, we show that valinomycin-induced apoptosis involves two different pathways in human NK cells: the predominant one is caspase-3 independent and the other caspase-3 dependent.