Primary immune response in skin and skin-associated lymphoid tissue of interleukin-1 transgenic mice

The interleukin-4 transgenic mice investigated here exhibit a ubiquitous ex pression of interleukin-4 in all organs, including the skin. In this study, the induction phase of oxazolone-induced local primary contact hypersensit ivity and croton oil-induced irritant contact dermatitis in transgenic and wild-type mice was analysed. Compared to wild-type mice, the transgenic mic e showed a decreased activation of the skin-draining lymph nodes but a stro ng hyperreactivity in the skin after topical sensitisation, In contrast to this, both the transgenic and the wild-type mice developed a strong and com parable inflammatory skin reaction after topical irritation. A striking inc reased expression level of tumour necrosis factor-alpha and macrophage infl ammatory protein-2 genes were found in the skin of the transgenic mice duri ng primary local contact hypersensitivity, while both the transgenic and th e wild-type mice developed comparable expression levels of these cytokines during irritant contact dermatitis, Compared to wild-type mice, a strongly enhanced expression level of interleukin-6 transcripts derived from epiderm al antigen presenting cells were detected in the skin of IL-4 transgenic mi ce, whereas in the skin-draining lymph nodes of transgenic mice significant ly lower levels were detected. We conclude that the migration of epidermal antigen-presenting cells towards the skin-draining lymph nodes is reduced i n transgenic mice, which could be due to the different cytokine balance in these mice strains. The atypical irritant-like reaction observed in transge nic mice after topical sensitisation is a phenomenon comparable to atopic d iseases and therefore this transgenic strain might be a helpful model for i nvestigating the immuno-pathophysiological features of these diseases.