Importance of HLA-DR+ and CD1a+ Epidermal Cells for Cytokine Production in Psoriasis

Abstract

Psoriasis is an inflammatory skin disease characterised by marked hyperproliferation of keratinocytes in association with vascular expansion, leukocyte infiltration and lymphocyte activation¹. Cytokines are thought to play a pivotal role in the pathogenesis. It is speculated that a dysregulation of the cytokine network involving tumor-necrosis-factor-a (TNF-α), interleukin-6 (IL-6) and interleukin-8 (IL-8) might be the basic mechanism of the psoriatic inflammatory response². TNF-α is the prototype of a proinflammatory peptide exerting immunomodulatory effects. IL-6 is a multifunctional cytokine with a broad range of biological functions in both acute and chronic inflammatory reactions. IL-8 is a potent chemotactic and activating factor for both neutrophils and lymphocytes. However, no information is available to which extent the production of these cytokines is (dys)regulated in psoriatic skin. Therefore, this study was meant to investigate the role of HLA-DR+ and CDla+ epidermal cells in the production of TNF-α, IL-6 and IL-8 in the autologous mixed skin lymphocyte reaction.