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, naive 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.