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

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.