Lysis of natural killer-sensitive and -resistant tumor cells by natural killer cytotoxic factors (NKCF)-containing liposomes.
The lethal hit stage in NK cell-mediated lysis requires a complex series of events involving the release of NKCF, subsequent binding of these factors to the target cell, and susceptibility of the target cell to lysis by NKCF. Binding of NKCF alone is not sufficient because a number of tumor cells are able to bind NKCF without being lysed, suggesting the need for an additional processing step active on susceptible target cells. In the present study, we show that the interaction with liposome-incorporated NKCF renders NK resistant target cells sensitive to NKCF-mediated lysis. These results suggest that NKCF may mediate their cytotoxic effects through internalization of these factors into the cytosol.
Roozemond
R C
RC
Department of Histology and Cell Biology, University of Amsterdam, The Netherlands.
Urli
D C
DC
Wright
S C
SC
Graves
S S
SS
Bonavida
B
B
D000818:Animals; D003602:Cytotoxicity, Immunologic; D005452:Fluoresceins; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D055646:Killer Factors, Yeast; D008081:Liposomes / Q000008:administration & dosage; D011506:Proteins / Q000008:administration & dosage / Q000276:immunology*; D014407:Tumor Cells, Cultured / Q000276:immunology*
D005452:Fluoresceins; D055646:Killer Factors, Yeast; D008081:Liposomes; D011506:Proteins; C024098:6-carboxyfluorescein