Cultured brain endothelium inhibits the cytocidal action of natural killer cells on glioma.
The killing of GL26 and YAC-1 cells by natural killer cells (NKC) is reduced in the presence of a monolayer of endothelial cells. This reduction in cytotoxicity correlates with the degree of adhesion between the tumor cells and the endothelial monolayers. The cytotoxicity of NKC toward glioma was 10% when carried out on plastic, but a monolayer of endothelium derived from brain inhibited the cytotoxicity by about 90%. Endothelium from thoracic duct and lung also inhibited cytotoxicity by about 90%, endothelium from aorta inhibited by 55% and that from ovary by only 45%. Cytotoxicity of NKC toward YAC-1 (a control NK target) was 40% on plastic, but a monolayer of endothelium from thoracic duct inhibited the cytotoxicity by 75%. Endothelium from brain and lung inhibited cytotoxicity by about 60%, aorta by 50%, and ovary by 40%. Interactions between tumor cells and the host-organ microvascular endothelium appear to protect neoplastic cells from natural surveillance mechanisms and may play a role in the formation of metastatic tumor deposits.
Neurology and Research Service, Wm. S. Middleton Memorial Veterans Administration Hospital, Madison, WI 53792.
J M
JM
Rozental
G M
GM
Kaminska
M J
MJ
Kaminski
D000818:Animals; D001921:Brain / Q000098:blood supply*; D004730:Endothelium, Vascular / Q000166:cytology* / Q000276:immunology; D005910:Glioma / Q000276:immunology*; D007694:Killer Cells, Natural / Q000276:immunology*; D051379:Mice; D014407:Tumor Cells, Cultured / Q000276:immunology*