Minimal antiproliferative effect of IFN-γ on A20 cells. (A) A FACS profile showing expression of IFN-γ receptor on A20 cells. A20 cells were stained with anti-CD119 (IFN-γ receptor α chain) (filled histogram) and with isotype control (open histogram). (B) Proliferation of A20 and WEHI-279 cells cultured in complete medium with increasing concentrations of mouse rIFN-γ. Cells were pulsed after 48 hours of culture with ³H-thymidine and harvested 16 hours later. Data are presented as the mean ± SD (cpm) of triplicate cultures in each culture condition. Results from 1 representative experiment of 3 are shown.