Study on the expression of IL-18, AcPL and IL-18BP mRNA in the psoriatic lesions

Abstract

To investigate the role of IL-18 and IL-18 binding protein (IL-18BP) in the pathogenesis of psoriasis, PT-PCR was used to semi-quantitatively analyze the mRNA expression of IL-18, AcPL (accessory protein-like) and IL-18BP in 12 psoriatic lesions and in 6 normal skin tissues. The results showed that IL-18 and AcPL mRNA were present in all specimens from 6 normal skin and 12 pieces of psoriatic skin, and IL-18 and AcPL showed relatively stronger intensity in the psoriatic skin compared with those seen in normal skin (P<0.01). Amplified bands indicating the expression of IL-18BP mRNA were weakly positive in all samples of normal skin. In contrast, the PCR products for IL-18BP were distinctly visible in all specimens of psoriatic lesions (P<0.01). These findings demonstrate that IL-18 is constitutively synthesized by human keratinocytes and involved in the development of the Th1 response in psoriatic lesions, and its bioactivity appears to be closely regulated by cutaneous inflammation.

Keywords

psoriasis vulgaris / interleukin-18 (IL-18) / AcPL / interleukin-18 binding protein

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