Constitutive expression of interferon beta in differentiated epithelial cells exposed to environmental stimuli.
The body's first line of defense against external challenge are the epithelial cells that line the skin and the respiratory, digestive, and genitourinary tracts. Inasmuch as interferon-beta (IFN-beta) participates in host defense against viral, bacterial, and parasitic infections and tumors, we hypothesized that this secreted protein is expressed in various murine epithelial cell types that line portals of entry to the body. We used immunohistochemistry and in situ hybridization techniques to measure IFN-beta expression in the various epithelial cell types and in internal murine organs sheltered from environmental stimuli. The epithelial cell types lining the skin, digestive tract, urinary tract, reproductive tract, and upper respiratory tract constitutively expressed IFN-beta. Specifically, all differentiated epithelial cells at risk of environmental exposure expressed IFN-beta (protein and mRNA) with the exception of the ciliated epithelial cells lining the lower respiratory tract. Epithelial cells of internal organs that are not directly exposed to external pathogens did not express IFN-beta.
Bielenberg
D R
DR
Department of Cell Biology, University of Texas M. D. Anderson Cancer Center, Houston 77030, USA.
Fidler
I J
IJ
Bucana
C D
CD
D000818:Animals; D002454:Cell Differentiation; D004781:Environmental Exposure; D004847:Epithelial Cells / Q000166:cytology / Q000276:immunology*; D005260:Female; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D016899:Interferon-beta / Q000032:analysis / Q000235:genetics*; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D009092:Mucous Membrane / Q000166:cytology / Q000276:immunology; D015345:Oligonucleotide Probes; D009928:Organ Specificity; D020545:Respiratory Mucosa / Q000166:cytology / Q000276:immunology; D012867:Skin / Q000166:cytology / Q000276:immunology; D014158:Transcription, Genetic
D015345:Oligonucleotide Probes; D016899:Interferon-beta