FIG. 7.

Epithelial cells of the intestine express functional IFN-λ receptor complexes. The response to in vivo electroporation of a plasmid encoding mouse IFN-λ3 was monitored by immunohistofluorescence staining for Mx1. The duodenum (section of the villi) of IFNAR1^0/0 mice is shown in low (A) and high (B) magnification. Prominent labeling of nuclear Mx1 is detected mainly in epithelial cells of the villi. (C) No such staining was observed in IFNAR1^0/0IL28Rα^0/0 mice, which cannot respond to IFN-λ. Strongly stained epithelial cells were detected in all regions of the gastrointestinal tract of IFN-λ-treated IFNAR1^0/0 mice, including esophagus (D), stomach (E), small intestine (F), and colon (G).