Figure 2.

P1's IFN-γ response and exploration of a possible dominant-negative effect. EBV-B cells from a healthy control, P1, P1's father and mother were stimulated with IFN-γ or IFN-α and subjected to western blot analysis for STAT1, Tyr701 phosphorylated STAT1 (A) or to EMSA for the assessment of GAF DNA-binding activities (B). (C) The GAF DNA-binding activities of EBV-B cells stimulated with various concentrations of IFN-γ were compared between a healthy control, P1 and P1's father. (D) GAF DNA-binding activities in the EBV-B cells were compared between a healthy control, individuals heterozygous for IFNGR1 or STAT1, P1 and patients with various IFNGR1, IFNGR2 and STAT1 mutations resulting in partial or complete deficiency, after stimulation with IFN-γ. The genotype of each cell line is written for the corresponding gene. (E) SV40-transformed fibroblasts from a healthy control were transfected with various plasmids encoding the WT or a mutant form of IFN-γR2. The various mutations included 186delC, 663del27 and 791delG, 382–87dup. Cells were also transfected with an IFNGR1 818del4 or STAT1 L706S expression plasmid as a positive control, for the detection of dominant-negative effects on IFN-γ signaling.