Figure 5.

Anti-IFN-γ autoAbs impair IFN-γ-induced STAT1 phosphorylation/expression and IRF1 expression/nuclear translocation. (a) Representative Western blotting shows blockade of IFN-γ (10 ng/ml)-induced STAT1 phosphorylation at Tyr701 (pY STAT1) and STAT1 protein expression by 10³ dilution of anti-IFN-γ autoAbs-contain patient sera (P1, P2, and P4) in human monocytic THP-1 cells incubated for 6 h. Relative ratio of measured proteins (pY STAT1/STAT1) are also shown. H, healthy control. Full-length blots/gels are presented in Supplementary Figure 2. Immunostaining followed by fluorescence microscopic observation was used to determine IRF1 expression (b) and nuclear translocation (c) in the indicated cells stimulated with IFN-γ (10 ng/ml) for 6 h with or without tested serum. Data are shown as a representative image.