A T-Cell/Collagen IV Connection in Psoriasis

Psoriasis has long been linked to T-cell–mediated autoimmunity. Although much work has focused on the nature of the participating T cells, the tissue-specific factors involved in the activation and expansion of tissue-residing effector T cells are not clear. The most important basement membrane collagen is collagen IV, the receptor of which — α₁β₁ integrin — is expressed by activated T cells. A research group in London recently examined the effect of α₁β₁ integrin expression on T cells in the pathogenesis of psoriasis.

The investigators first demonstrated that in lesional psoriatic skin, α₁β₁ expression was restricted to epidermal, rather than dermal, T cells and that epidermal α₁β₁+ cells had a phenotype characteristic of effector memory T …