Fig. 6. TNF--induced cell scattering is mediated by TNF-R1. (A,B) 2A4 cells were seeded in plastic wells in DMEM-F12 medium supplemented with ITS+ Premix and grown for 24 hours. The cultures were then incubated for 2 hours with 40 µg ml^-1 hamster monoclonal antibodies to either mouse TNF-R1 or TNF-R2 before addition of 10 ng ml^-1 TNF-. Pictures were taken 72 hours later. TNF--induced scattering is blocked by the anti-TNF-R1 antibody (A) but not by the anti-TNF-R2 antibody (B). (C,D) 2A4 cells were suspended in a collagen gel in defined medium. Goat irrelevant IgG (C) or goat anti-TNF-R1 agonist antibody (50 µg ml^-1) (D) were added both to the gel at the time of cell embedding and to the medium above the gel. The anti-TNF-R1 agonist antibody has induced 3D scattering of 2A4 cells (D). Scale bars, 10 µm.