Figure 1. Transgenic IFNAR1 is expressed specifically on T cells of IFNAR1^Texcl mice and is functionally active.

(A) Construct used to generate cd2–ifnar1 transgenic mice. (B) RT-PCR demonstrated lymphoid tissue-specific expression of transgenic ifnar1. With the use of a reverse primer for FLAG, this PCR reaction amplified the ifnar1 transcript only from transgenic mice. Br, Brain; Liv, liver; Lu, lung; Sp, spleen; Th, thymus. (C) RNA was extracted from CD3⁺-enriched T cells, and ifnar1 mRNA was amplified by real-time RT-PCR. (D) Splenocytes from WT, Ifnar1^−/−, and IFNAR1^Texcl mice were stained for CD3, CD19, and IFNAR1. (E and F) Splenocytes were stimulated by IFN-α/β (250 U/ml) for 30 min (E) or for the indicated time (F) and then analyzed by Western blot. STAT1 and p-STAT1, 89/91 kDa; ISG15, 15 kDa; actin, 42 kDa. The images were spliced and joined, as indicated by white lines for the sake of the presentation. (G) Thymocytes were incubated with anti-IFNAR1-neutralizing antibody before IFN-α/β treatment and stained with a p-STAT1 antibody. The histogram plots show the p-STAT1-positive cells in the total live-cell gate (IFN treatment, bold, black line; antibody + IFN treatment, black line; no treatment, dotted line).