INDUCTION OF NATURAL-KILLER-CELL MIGRATION BY MONOCYTE CHEMOTACTIC PROTEIN-1, PROTEIN-2 AND PROTEIN-3

Under certain physiological and pathological conditions, naturall kill er (NK) cells rapidly accumulate in tissues. Chemokines are an essenti al component of the current paradigm of leukocyte recruitment. The pre sent study was designed to investigate the responsiveness of NK cells to the prototypic C-C chemokine, monocyte chemotactic protein-1 (MCP-1 ). MCP-1 induced migration across filters of interleukin (IL)-2-activa ted NK cells, whereas it was a weak attractant for unstimulated cells. Maximal induction of migration required a positive concentration grad ient between the lower and the upper compartment of the chemotaxis cha mber. Preliminary characterization of the MCP-1 receptor on NK cells i ndicated that the chemotactic response to MCP-1 was blocked by pre-tre atment of cells with Bordetella pertussis toxin, and MCP-1 but not IL- 8 displaced I-125-labeled MCP-1 from IL-2-activated NK cells. The rela ted chemokines MCP-2 and MCP-3 were also active - though less potent a ttractants for activated NK cells. Thus the spectrum of action of MCP- 1, -2 and -3 encompasses NK cells and chemokines are likely to play a role in regulating extravasation of these cells.