Circulating exosomes regulate T-cell-mediated inflammatory response in oral lichen planus

Background Exosomes are newly recognized natural nanocarrier and intercellular messenger that emerge as important mediators of signal transmission. Exosomes have been reported to modulate the inflammatory response of a number of diseases. This study investigated the effects of circulating exosomes from oral lichen planus (OLP) on T cells. Methods Plasma-derived exosomes were purified from both OLP patients and control groups. T cells were observed under a confocal laser scanning microscope after co-cultivation with PKH67 labeled exosomes for 12, 24, and 48 hours. The effects of exosomes exposure on T cells were analyzed with several functional assays, investigating proliferation, apoptosis, and migration. Production of interleukin (IL)-2, -4, -10, and interferon (IFN)-gamma was measured via enzyme-linked immunosorbent assay. Results PKH67-labeled exosomes were taken up by T cells in a time- and dose-dependent manner. Several biological functions of T cells were promoted. In particular, the circulating erosive OLP exosomes significantly enhanced T-cell proliferation and attenuated the apoptosis. The migration capacity of T cells increased remarkably in response to erosive OLP exosome treatment. In addition, the ratio of IFN-gamma/IL-4 was significantly elevated in OLP patients. Conclusions Our findings indicate that the circulating OLP exosomes are involved in the biological functions of T cells, potentially promoting the OLP progression by regulating the T-cell-mediated inflammatory response.