Interferon beta (IFN β) is a member of the family of secreted proteins that compose the host defense against viral, bacterial, and parasitic infections and tumors. The interferons exert their activity indirectly by regulating a number of other proteins. Low level expression of IFN β has been reported in a variety of non-epithelial cells from normal animals. Here, we demonstrate the expression of IFN β in epithelial cells lining organs that are chronically exposed to a variety of environmental challenges.

Tissue samples from the digestive system, urinary bladder, mammary fat pad, skin and cornea of C3H/HeN mice were fixed with 10% formalin and processed for histology. Immunoperoxidase was performed on tissue sections that had been de-waxed and treated with trypsin. Briefly, the sections were incubated with rabbit anti mouse IFN β (Lee Biomolecular, San Diego, CA) overnight at 4°C, washed and incubated further with a peroxidase conjugated goat anti-rabbit IgG, (F(ab) 2) (Jackson ImmunoResearch Laboratories, Inc., West Grove, PA) for 1 h at ambient temperature.