Figure 7.

MSCs derived from the skin of patients with psoriasis show biological alterations. The nonlesional skin of patients with psoriasis already has a microenvironment that affects some characteristics of MSCs. The NLE-MSCs show alterations in their morphology and low proliferation. In addition, NLD-MSCs present a high HLA-I expression and do not have immunosuppression capacity against T lymphocytes; both of these aspects may be associated with an increase in antigen presentation, and therefore, such MSCs may be the initial stimuli for the overactivation of T cells and favor the development of psoriatic lesions. The exacerbated inflammation in lesional areas could favor the recruitment of MSCs and their activation. Several studies have shown that an inflammatory environment stimulates the secretion of trophic factors and immunosuppressive capacity by MSCs. Thus, the presence of MSCs in the lesional dermis and epidermis could contribute to the incomplete expansion and differentiation of epidermal stem cells; in addition, to their low immunosuppressive capacity, they would also favor the maintenance of these lesions.