Toward a canine model of atopic dermatitis: amplification of cytokine‐gene transcripts in the skin of atopic dogs

Abstract

Abstract: The objectives of the present study were to characterize and compare the repertoire of cytokine‐genes transcribed in skin homogenates obtained from normal dogs and dogs with atopic dermatitis (AD) using a reverse‐transcriptase polymerase chain reaction and canine‐specific cytokine‐gene primers. Whereas IL‐4 and IL‐5 cytokine‐gene transcripts were detected more commonly in atopic skin biopsy homogenates, IL‐2 mRNA was amplified more often from normal control specimens. IFN‐γ mRNA was detected in 5/29 atopic specimens, 4 of them obtained from the only dog with chronic skin lesions. One‐fourth of atopic samples exhibited clear type‐2 cytokine profiles; the remainder did not demonstrate polarized repertoires. Conversely, type‐1 cytokine profiles were characterized in one‐fourth of normal control specimens. The present study establishes, for the first time, the transcription of type‐2 cytokine‐genes in the skin of dogs with AD. Future experiments investigating the cellular origin and dynamics of allergic cytokine‐gene transcription are needed to confirm whether or not canine AD could be considered an immunological model for a human disease.