Expression and biological functions of the CCL5‐CCR5 axis in oral lichen planus

Abstract Oral lichen planus (OLP) is a chronic inflammatory oral mucosal disorder with T cell‐mediated immunological pathogenesis. C‐C motif chemokine ligand 5 (CCL5) and its receptor C‐C motif chemokine receptor 5 (CCR5) play important roles in the activation and recruitment of T cells. This study sought to explore the expression and biological functions of the CCL5‐CCR5 axis in OLP. We examined the expression of the CCL5‐CCR5 axis in the peripheral blood and oral tissue of healthy controls and patients with OLP using quantitative real‐time PCR, Simple Western assays, enzyme‐linked immunosorbent assay (ELISA) and immunohistochemistry. In addition, we investigated the effects of the CCL5‐CCR5 axis on the proliferation, apoptosis and migration of OLP T cells using Cell Counting Kit‐8 (CCK8) assay, flow cytometry and transwell assay. We found that the expression of the CCL5‐CCR5 axis was significantly elevated both in the peripheral blood and oral tissue of patients with OLP compared with healthy controls. CCL5 not only promoted OLP T‐cell proliferation and migration but also inhibited OLP T‐cell apoptosis. Moreover, CCR5 inhibition suppressed OLP T‐cell proliferation and migration, whereas OLP T‐cell apoptosis was promoted. In conclusion, our data suggest that the CCL5‐CCR5 axis may be closely related to the inflammatory infiltration of T cells in OLP.