Fig. 5.

Purified IgG from anti-IFN-γ IgG-positive SLE patients neutralized IFN-γ. (A) Total IgG purified from anti-IFN-γ IgG-positive SLE patients interfered with the detection of human IFN-γ. Serially diluted IgG was respectively incubated with a fixed concentration (8 ng/ml) of IFN-γ. The amount of remaining unbound IFN-γ was detected by ELISA. (B-C) The phosphorylation of STAT1 (S727) was significantly decreased by anti-IFN-γ IgG in THP-1 cells. (B) Representative data for western blots. (C) Grayscale statistical map for western blots. Values were represented as means ± standard deviation (SD). *p < 0.05, **p < 0.01, ***p < 0.001. SLE, systemic lupus erythematosus; ELISA, enzyme-linked immunosorbent assay; STAT1: signal transducer and activator of transcription1. pSTAT1: phosphorylated-STAT1