Photobiomodulation suppresses allergic contact dermatitis by inhibiting T‐cell activation

Abstract Background Allergic contact dermatitis (ACD) is a dermal inflammatory disease caused by allergic reactions to substances that contact the skin. The hyperactivation of T cells plays an important role in its pathogenesis. Photobiomodulation (PBM) is an efficacious therapeutic approach for suppressing inflammatory diseases. Objective This study aimed to evaluate the potentially beneficial role of PBM in ACD models and investigate its possible mechanisms. Methods In this study, the ACD model of C57BL/6 mice was produced and treated with PBM, and the number of T cells was evaluated. In an in vitro study, naïve T cells were isolated and intervened with PBM. The markers of T cell activation were detected by flow cytometer. Transforming growth factor‐β (TGF‐β) and reactive oxygen species (ROS) were detected to investigate the mechanism. Results PBM effectively inhibited the inflammatory response by impeding the number of T cells in the ACD model. And in vitro studies showed that PBM could directly moderate the activation of naïve T cells and possess the capability to impede T cell activation via TGF‐beta signaling pathway. Conclusion Our finding elucidates the potential mechanism underlying the inhibitory effects of PBM in inflammatory diseases and furnishes a theoretical foundation for its clinical application.