Identification of the Effect of Amphiregulin on Keratinocytes and T Cells in Psoriasis

Abstract

Background

In addition to its fundamental functions in mediating the survival, proliferation, and migration of keratinocytes, increasing evidence suggests that the amphiregulin-epidermal growth factor receptor pathway has a major impact on cutaneous inflammation. Transgenic expression of amphiregulin in the epidermis of mice induces skin pathology with striking phenotypic similarity to that of psoriasis. Prominent T-cell and dendritic cell infiltrates are observed in the lesional skin from these mice.

Objective

In this study, we aimed to identify more fully the effect of amphiregulin on keratinocytes and T cells during cutaneous inflammation through examining relevant cytokines in the lesional skin as well as in human keratinocyte culture.

Methods

Using a multicytokine enzyme-linked immunosorbent assay, we found that amphiregulin directly induces the production of monocyte chemoattractant protein-1, interleukin-α, and interleukin-8 from keratinocytes in vitro. In addition, we examined the cutaneous expression of T-cell cytokines in amphiregulin transgenic mice compared with wild-type mice using quantitative polymerase chain reaction, which demonstrated upregulation of interferon-γ, vascular endothelial growth factor, and interleukin-4 in amphiregulin transgenic mice.

Results and Conclusion

Our study suggested that amphiregulin in the epidermis not only induces keratinocyte proliferation but also induces T-cell activation through a complex circuit of proinflammatory cytokines. Elucidating the role of amphiregulin on the generation, interactions, and balance among T-cell subsets will advance the understanding of psoriasis pathogenesis.