Abstract
BACKGROUND: Oral ulcer (OU) is among the most common oral mucosal disease, and immune factors are generally considered to play crucial roles in OU. Photobiomodulation (PBM) therapy can promote healing and alleviate pain; however, the effect and mechanism of early ulceration remain unclear. OBJECTIVE: This study aimed to establish a model of early persistent aggravation, assess the impact of PBM on early persistent aggravation, and map the involvement of different immune cells. METHODS: In this study, an OU model was established in C57BL/6 mice, and the mice were subsequently treated with PBM. Haematoxylin and eosin staining, stem cell immunofluorescence, and collagen III immunohistochemical staining were used to evaluate the wound healing process. Flow cytometry and immunohistochemistry were used to assess changes in various immune cells, including neutrophils, macrophages, T cells, and B cells. RESULTS: PBM effectively inhibited the aggravation of early ulcers and inflammation by decreasing the number of neutrophils and Th1 cells while promoting the polarization of macrophages towards the M2 phenotype and the generation of regulatory T cells (Tregs). CONCLUSION: Our study investigated the PBM-induced patterns of changes in various immune cells during the development of OU, thereby facilitating understanding of the disease and providing a theoretical basis for the clinical application of PBM.