Alterations of T-cell: extracellular matrix proteins interactions in psoriasis.

Recent data indicate that extracellular matrix proteins (collagens, fibronectin) co-stimulate T-cell lymphoproliferative responses in vitro. We have studied the co-stimulatory activities of those proteins in patients with psoriasis, a disease in which T cells infiltrating the skin are continuously exposed to collagen and fibronectin. CD3-triggered T-cell proliferative responses were lower in psoriasis but could be enhanced by collagens I and IV and fibronectin. Interestingly, collagen-I-dependent co-stimulation was markedly decreased in patients with psoriasis, while there was a trend towards the enhancement of collagen-IV-induced responses. Those disturbances were most frequently seen in patients with active and widespread lesions. It appears that abnormalities of extracellular matrix protein-derived signals could play a role in the immunopathology of psoriasis.