title: Interleukin-10 inhibits the elicitation phase of allergic contact hypersensitivity.
abstract: Interleukin-10 (IL-10) is known to play a major role in suppressing immune and inflammatory responses by inhibiting the production of proinflammatory cytokines. Therefore, we hypothesized that IL-10 might be capable of suppressing allergic contact hypersensitivity. BALB/c mice were sensitized on the dorsal skin with dinitrofluorobenzene and challenged on the ears 6 d later. The effect of IL-10 on the elicitation phase of contact sensitization was determined by its intradermal injection into the pinnae of the mice at doses of 0.1-100 ng. At 24 and 48 h after challenge, ear swelling was suppressed in a dose-dependent manner by injection of IL-10 at doses of 10-100 ng. Maximal inhibition of ear swelling (46.9%) was observed after injection of 100 ng of IL-10. IL-10-injected ear skins showed less inflammatory cell infiltration and decreased edema at the dermis compared with controls. Because IL-10 is known to inhibit Th1 cytokines such as interferon-gamma, we examined whether the suppressive effect of IL-10 on ear swelling was accompanied by IL-10-induced inhibition of interferon-gamma. We found that IL-10 application suppressed interferon-gamma mRNA upregulation in challenged skin. Our results suggest that IL-10 significantly modifies the elicitation of allergic contact sensitivity reactions.
authors.affiliation: Division of Dermatology, Sunnybrook Health Science Centre, University of Toronto, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Kondo
authors.forename: R C
authors.initials: RC
authors.lastname: McKenzie
authors.forename: D N
authors.initials: DN
authors.lastname: Sauder
mesh_terms: D000818:Animals; D017449:Dermatitis, Allergic Contact / Q000209:etiology / Q000517:prevention & control*; D004139:Dinitrofluorobenzene; D005260:Female; D007371:Interferon-gamma / Q000235:genetics; D016753:Interleukin-10 / Q000627:therapeutic use*; D051379:Mice; D008807:Mice, Inbred BALB C; D012333:RNA, Messenger / Q000032:analysis
chemical_list: D012333:RNA, Messenger; D016753:Interleukin-10; D007371:Interferon-gamma; D004139:Dinitrofluorobenzene