engleski

Immunohystochemical analysis of psoriatic lesions suggest active involvement of perforin molecule in the creation of psoriatic plaque

It seems that in psoriatic lesions proinflammatory cytokines released by activated CD4+ and CD8+ T cells generate keratinocyte proliferation and abnormal differentiation, a hallmark of psoriasis. However, the role of cytotoxic molecules, released by CD8+ T cells and NK cells, in the development of psoriatic lesions, is still not clear. Both, cytotoxic T cells and NK cells mediate cytotoxic reactions by two different mechanisms, perforin/granzyme and Fas/FasL pathway. In the present study, we analysed the distribution of perforin, T and NK cell subsets by immunohistochemistry. Skin biopsy specimens obtained from lesional psoriatic skin, non-lesional and healthy skin were analysed by immunohistochemistry. We observed strong expression of CD4+ and CD8+ T cells in the dermis and epidermis of psoriatic lesions but not in the non-lesional and healthy skin. Perforin-expressing cells were found with strong positivity mainly in the epidermis of psoriatic lesions in close contact with the damaged keratinocytes. Our study clearly showed that T lymphocytes might be responsible for inducing damage to keratinocytes by releasing cytolytic molecules as perforin itself.

psoriasis; T cells; perforin

DOI: 10.1111/j.1468-3083.2004.01152.x