Polarization of the Golgi apparatus and the microtubule-organizing center within cloned natural killer cells bound to their targets.

In cell couples formed between a cloned murine natural killer (NK) cell and either of two target cells, we have obtained evidence by immunofluorescence observations for a rapid coordinate repositioning of two organelles, the microtubule organizing center and the perinuclear Golgi apparatus, inside the NK cell to face the region of contact with the target cell. With microtubule-disrupting drugs, which also cause a dispersion of the Golgi apparatus throughout the periphery of the NK cell, it was found that target cell lysis is reversibly inhibited. It is proposed that the coordinate repositioning of the two organelles serves the function of directing secretory vesicles derived from the Golgi apparatus to the bound target cells, the secretory vesicles containing components that induce target cell lysis.