Actions of Tumor Necrosis Factor on Cultured Vascular Endothelial Cells: Morphologic Modulation, Growth Inhibition, and Cytotoxicity

Exposure to highly purified preparations of murine tumor necrosis factor (TNF) resulted in distinct morphologic changes and proliferation inhibition of cultured endothelial cells from the bovine aorta and capillary and of those from the human umbilical vein. The TNF preparation also inhibited the proliferation of bovine aortic smooth muscle cells but failed to inhibit the proliferation of bovine and human fibroblasts. The cytotoxic activity of the TNF preparation was prominent only in bovine capillary endothelial cells. Upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis (PAGE), and upon PAGE only, of the TNF preparations, the fractions representing growth inhibitory and cytotoxic activities against bovine capillary endothelial cells exactly corresponded to those containing migrated TNF. Treatments of the TNF preparations with heat and polymyxin B revealed that the effects on endothelial cells were not due to possibly contaminated endotoxin. Moreover, growth inhibitory and cytotoxic actions of rabbit TNF on bovine capillary endothelial cells were completely neutralized by the addition of an anti-rabbit TNF monoclonal antibody. These results suggest that TNF causes morphologic changes in, growth inhibition of, and cytotoxicity against, the vascular endothelial cells.