Neutralization of biological activities of rhu IFN-γ by recombinant chimeric protein. Panel A: Inhibition of antiproliferative activity of IFN-γ. The inhibition of antiproliferative action of 4 IU/ml of IFN-γ by 50 μg/ml AnTH1 proved to be statistically different (p < 0.05) by the Kruskal-Wallis test. The data are results from 3 independent experiments. The dilutions tested for the antagonist were: 1 (1:4), 2 (1:8), 3 (1:16), 4 (1:32), and 5 (1:64). The OD 580 nm of cells without IFN-γ at the beginning of the experiment was 0.139 and after 72 hours on culture was 1.068. Panel B: Inhibition of the IFN-γ induced HLA-DR by the AnTh1. The inhibition of IFN-γ (500 IU/mL) HLA-DR stimulation by 1.5 μg/ml AnTh1 proved to be statistically different (p < 0.05) by the Kruskal-Wallis test. The data are the results from 3 independent experiments. The amount of IFN-γ was denoted as IU of antiviral activity, where 1 IU is defined as the inverse of the dilution that conferred 50% protection to the monolayer of cells infected with a virus.