title: Detection of a specific inhibitor of interleukin 1 in sera of UVB-treated mice.
abstract: It was recently demonstrated that murine keratinocytes upon irradiation with ultraviolet (UV) light release an immunosuppressive cytokine which blocks the biological activity of interleukin 1 (IL 1). This epidermal cell derived inhibitor (EC-contra IL 1) exhibits a molecular weight of 40 kD and a pI of approximately 9.0. EC-contra IL 1 in vivo possibly may penetrate through the basal lamina and subsequently cause systemic immunosuppression following UV-exposure. In the present study, we tested whether EC-contra IL 1 can also be detected in vivo. Serum samples obtained from total body UV-exposed mice were subjected to HPLC gel filtration and tested for IL 1 inhibitory activity. While a non-specific high molecular weight (300 kD) suppressor factor was detected in sera of both UV-exposed and sham treated control mice, a specific IL 1 inhibitor exhibiting a molecular weight of 40 kD was observed only in sera of UV-exposed mice. This cytokine named serum-contra IL 1 was maximally released 24 h after UV-exposure, exhibited a pI of 9.0, and blocked the activity of natural as well as recombinant interleukin 1 in a dose dependent manner. Serum-contra IL 1 did not suppress interleukin 2 or interleukin 3 and did not inhibit spontaneous cell proliferation. The present biochemical and biologic data suggest that serum-contra IL 1 and EC-contra IL 1 appear to be closely related if not identical. These observations therefore indicate that keratinocytes upon UV-irradiation in vivo release EC-contra IL 1 which may at least partly be responsible for the immunosuppression following UV-exposure.
authors.affiliation: Department of Dermatology, Hospital Vienna Lainz, Austria.
authors.forename: T
authors.initials: T
authors.lastname: Schwarz
authors.forename: A
authors.initials: A
authors.lastname: Urbanski
authors.forename: R
authors.initials: R
authors.lastname: Kirnbauer
authors.forename: A
authors.initials: A
authors.lastname: Köck
authors.forename: F
authors.initials: F
authors.lastname: Gschnait
authors.forename: T A
authors.initials: TA
authors.lastname: Luger
mesh_terms: D000818:Animals; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006863:Hydrogen-Ion Concentration; D007375:Interleukin-1 / Q000037:antagonists & inhibitors* / Q000097:blood; D051379:Mice; D008970:Molecular Weight; D014466:Ultraviolet Rays; D014916:Whole-Body Irradiation
chemical_list: D007375:Interleukin-1