Stimulation of TLR4 expression in human mononuclear phagocytes by IFNγ.

(A) TLR4 surface expression in human monocytes and macrophages exposed to IFNγ or IFNβ (500 U/mL, 24 hours) compared with cells treated with medium alone (Ctr). MCF is indicated for each treatment. Dotted line indicates irrelevant control mAb. (B) Human monocytes were treated with IFNγ (500 U/mL) or with medium alone (Ctr) for 4 or 24 hours and analyzed for their TLR4, MD-2, and MyD88 mRNA content by Northern blotting. The lower part of the panel shows the ethidium bromide staining, after RNA transfer to the membrane. Western analysis is also shown for MyD88 (IFNγ, 500 U/mL, 24 hours).