Cytokine mRNA expression in an in vitro human skin model, SKIN2(TM)

SKIN2(TM) ZK1300 is a three-dimensional human skin model consisting of multilayered dermal fibroblasts and well-differentiated epidermal keratinocyte layers, including a stratum corneum. To characterize this model better, constitutive levels of cytokine gene expression were determined. Reverse transcriptase-polymerase chain reaction (RT-PCR), followed by liquid hybridization to labelled internal probes, demonstrated that interleukin (IL)-1I, IL-1 beta, IL-6, IL-8, IL-10, tumour necrosis factor (TNF)I, granulocyte macrophage-colony stimulating factor (GM-CSF), transforming growth factor (TGF beta 1) and IL-12 p35 mRNAs were constitutively expressed whereas IL-12 p40 was not. The contribution of the dermal component of this human skin model (Model ZK1100) was further characterized by determining constitutive cytokines expressed and their modulation by phorbol 12-myristate, 13-acetate (PMA). The dermal component, consisting of multilayered human dermal fibroblasts, constitutively expressed message for IL-II, IL-1 beta, IL-6, IL-8, TGF beta 1, GM-CSF and IL-12 p35. Message was not detected for IL-10, TNFI or IL-12 p40. PMA treatment of the multilayered dermal fibroblasts increased steady-state mRNA levels of IL-II, IL-1 beta, IL-6, IL-8, GM-CSF and TGF beta 1, but did not induce IL-10, TNFI or IL-12 p40 expression at the dose and times tested. In summary, these studies demonstrate that the SKIN2(TM) three-dimensional human skin cultures, and their dermal component, constitutively express mRNA for an array of inflammatory and immunomodulatory cytokines, and that PMA exposure modulates mRNA levels of the dermal cytokines. Copyright (C) 1996 Elsevier Science Ltd.