Correlation between ultrastructural and histochemical parameters in lymphokine-activated killer (LAK) cells reacting with target cells in vitro.

Ultrastructural and fluorescence data allowed us to study the most important moments of the interaction between lymphokine-activated killer (LAK) cells against target cells (Chang) in vitro. The LAK cells, maintained at low doses of recombinant interleukin-2, were able to recognize, bind and destroy the tumoral cells. Before the attack, the LAK cells were characterized by a cytoplasm with a high ribosomes content; after the identification and the interaction cell-cell, a degeneration of the tumoral cell was observed. These observations allowed us to suppose that the interaction between the two types of cells may be mediated by a receptoral membrane system without the action of lytic enzymes.