Human Keratinocytes Constitutively Express Interleukin-18 and Secrete Biologically Active Interleukin-18 After Treatment with Pro-Inflammatory Mediators and Dinitrochlorobenzene

Interleukin-18 is a potent inducer of interferon-γ by activated T cells, macrophages, and monocytes and is synthesized as an inactive precursor. Pro-interleukin-18 must be cleaved by interleukin-1-β-converting enzyme for secretion of the biologically active form. We report that among selected non-bone marrow derived skin cells, interleukin-18 mRNA is constitutively expressed by human keratinocytes and not by dermal microvascular endothelial...