MicroRNA-155 inhibits the proliferation of CD8(+) T cells via upregulating regulatory T cells in vitiligo

It has been reported that loss and degradation of epidermal melanocytes is closely associated with the pathogenesis of vitiligo. In addition, CD8(+) T and regulatory T (Treg) cells serve an important role during these two processes. MicroRNA-155 (miR-155) is known to contribute to the pathogenesis of vitiligo; however, the mechanism by which miR-155 regulates the development of vitiligo remains unclear. In the present study, naïve T and CD8(+) T cells were isolated from a patient with non-segmental vitiligo by flow cytometry. The cells were differentiated into Treg cells by treatment with interleukin-2, transforming growth factor-β and retinoic acid. In addition, miR-155 agonists and antagonists were used to investigate the effect of miR-155 on the proliferation of CD8(+) T cells, Treg cells and melanocytes. The results demonstrated that the miR-155 agonist significantly decreased the rate of CD8(+) T cell growth, as well as promoted the proliferation of melanocytes by inducing an increase in the percentage of Treg cells. By contrast, the miR-155 antagonist inhibited the proliferation of melanocytes by decreasing the percentage of Treg cells. miR-155 protected melanocyte survival by increasing the number of Treg cells and by decreasing the number of CD8(+) T cells. Therefore, these data may provide a new prospect for the treatment of vitiligo.