P28 The changes in the number and subsets of regulatory T cells in the skin of psoriasis mice: implications for the progression and outcome of psoriasis

Abstract Regulatory T cells (Treg) are indispensable in immune suppression due to their suppressive function, which prevents autoimmunity and tissue damage caused by excessive or unnecessary immune activation. A significant increase in the number of Treg cells can be observed in the psoriatic lesions of mice; however, the underlying mechanism remains unclear. This study, based on the changes in the number of Treg cells, explored the variations in Treg numbers and phenotypic differences at different stages. It was found that the number of Treg cells increased with the progression of the disease and decreased during the remission phase, with their suppressive function being compromised. This is attributed to the fact that the proliferating Treg cells during the disease exacerbation are primarily a subset with impaired immune suppression. Therefore, we propose that methods to restore the number of Treg cells with high suppressive function could be beneficial for the amelioration of psoriasis.