Infiltration and lysis of tumour cell aggregates by adherent interleukin-2-activated natural killer cells is distinct from specific cytolysis.
Adoptively transferred activated natural killer (A-NK) cells infiltrate tumours in vivo. Two in vitro B16-F10 melanoma tumour models were used to study with fluorescence and electron microscopy the infiltration of adherent interleukin 2 (IL-2) A-NK cells: (1) substratum-bound sessile microtumours (MTs), and (2) three-dimensional cell growth on macroporous gelatinous microcarriers (Cultispheres). From 2 h and on increasing numbers of A-NK cells infiltrated the MTs regularly surrounded by a widened intercellular space. An IL-2-dependent disintegration of MTs began at 6-8 h resulting in a release of vital and dead cells. A-NK cell invasion into Cultispheres effectively displaced the melanoma cells from the highly convoluted substratum. Thus, A-NK cell infiltration had a protease-like effect on the tumour cell aggregates which might have a bearing on the interpretation of their cytolytic effect on target cells. Ultrastructural evidence was not obtained of specific A-NK/target conjugate formation or of granule-mediated target cell destruction in either model tumour.
Johansson
B R
BR
Institute of Anatomy and Cell Biology, University of Göteborg, Sweden.
Unger
M L
ML
Albertsson
P
P
Casselbrant
A
A
Nannmark
U
U
Hokland
M
M
D019264:Adoptive Transfer; D000818:Animals; D002448:Cell Adhesion / Q000276:immunology; D002449:Cell Aggregation / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D007376:Interleukin-2 / Q000494:pharmacology*; D015979:Killer Cells, Lymphokine-Activated / Q000187:drug effects / Q000276:immunology* / Q000648:ultrastructure; D008213:Lymphocyte Activation; D008297:Male; D008546:Melanoma, Experimental / Q000276:immunology* / Q000648:ultrastructure; D051379:Mice; D008810:Mice, Inbred C57BL; D014407:Tumor Cells, Cultured
D007376:Interleukin-2