engleski

Perforin expression in skin lesions of psoriatic patients

Psoriasis is T cell mediated autoimmune skin disease characterized by infiltration of inflammatory cells, especially T lymphocytes and production of inflammatory cytokines, mostly of Th1 type. Oscillations in phenotype of T lymphocytes are observed in peripheral blood (PB) and skin lesions, depending on stage of disease. CD4+ T cell predominance in exacerbated psoriatic plaques and CD8+ T cells in resolutive lesions are demonstrated. Cell mediated cytotoxicity reactions (CMC) are reactions mediated by secretion of cytolytic molecule perforin and granzyme or binding of FasL (CD95L) with Fas receptor (CD95) on target cell. CD8+ T lymphocytes and to a certain degree CD4+ T lymphocytes as well as NK cells mediate in CMC. Perforin (P) is cytolytic molecule expressed in the granules of cytolytic cells both CTL and NK cells, released in the contact with the target cells subsequently exerting either necrotic or apoptotic (in collaborations with serine esterases) cell death. Our former results point on participation of cytolytic mechanisms in immunopathogenesis of psoriasis. Perforin expression is upregulated in peripheral blood T lymphocytes (especially CD8 phenotype) and CD56+ NK cells in exacerbation phase of psoriasis vulgaris compared to remission. Thus, role of cytolytic pathway mediated by perforin is recognized in psoriasis in PBL and in lesions but still insufficiently defined. The aim of our new investigation was to analyze expression of perforin in the psoriatic skin lesions and highlight a role of perforin mediated cytotoxicity in pathophysiology of disease. Skin biopsies of eight psoriatic patients, four in exacerbation and four in remission phase of psoriasis vulgaris were investigated. They were obtained from inside border of stable plaque (in a case of remission) and newly exacerbating plaque (exacerbating phase) and from uninvolved skin of the same patients biopsied at least 3 cm away of affected skin. Single immunoenzyme staining was performed using biotin-streptavidin-peroxidase method. Our preliminary results showed stronger perforin expression in involved psoriatic skin in exacerbating phase compared to remission. The same tendency of increasing number of cells in exacerbation phase was noticed among CD56+ NK population. These results point on the potential role of cytolytic mechanisms mediated by perforin compared to remission of disease.

psoriasis; cell mediated cytotoxicity; NK mediated cytotoxicity; perforin; skin lesions

DOI: 10.1046/j.1468-3083.16.s1.1.x