Selective impairment of downstream gene induction in the cells of P1. (A) The K201N allele has normal transcriptional activity. U3C cells were transfected with M, WT, and K201N mutant alleles, with firefly luciferase under IRF1 or IFIT1 promoters and a Renilla luciferase control, and stimulated with 103 IU/mL IFN-γ or IFN-α for 24 hours. (B) Hotmap of 2 categories of ISGs quantified by quantitative PCR in SV40-fibroblasts from P1, with comparison of the results obtained for WT/WT, L706S/WT, P696S/P696S, and −/− subjects. The induction of CCL2, CXCL10, and IRF8 was significantly impaired in the cells of P1, as shown by comparison with 5 healthy controls. These genes are identified as “STAT1 pulse-dependent primary ISGs”; CXCL9, GBP1, CIITA, and IRF1 displayed a similar pattern in the cells of P1 and controls and are designated as “non-STAT1 pulse-dependent primary ISGs.” (C) After stimulation with 103 IU/mL IFN-α, CXCL9 induction was significantly impaired in EBV-B cells from P1, at 1-hour and 2-hour time points. However, the level of induction of CXCL9 in the cells of P1 remained higher than those in P696S/P696S and −/− EBV-B cells. The results are representative of 3 independent experiments. One red asterisk indicates P < .05; and 3 red asterisks indicate P < .005.
