ABSTRACT
Exosomes are membranous vesicles secreted by cells and can be widely involved in intercellular communication, anti-inflammation, immunoregulation, etc.Mesenchymal stem cell (MSC), regulatory T cell (Treg), immature dendritic cell (imDC) and myeloid-derived suppressor cell (MDSC) are the main ocular surface-related exosomes origins.Exosomes derived from different cells play their roles by delivering different biological molecules to recipient cells.Exosomes derived from MSC play a positive role in ocular surface inflammation and immune-related diseases by inhibiting T cell proliferation, transforming macrophage phenotype, regulating T helper (Th) cell differentiation and up-regulating Treg expression, reduce neovascularization and inflammation, and foster a microenvironment to promote corneal wound healing at the same time.Exosomes derived from Treg contain inducible NO synthase and microRNA (miRNA) including miR-503, miR-330 and miR-9, which can interfere with cell cycle progression, induce apoptosis, induce the differentiation of other T cells into Treg phenotype, inhibit T cell allograft rejection to induce immune tolerance.Exosomes derived from imDC inhibit corneal allograft rejection by delivering miR-682.MDSC-derived exosomes promote Treg expansion in vivo and in vitro, inhibit the proliferation and cytotoxicity of activated T cells, and express miR-29a-3p and miR-93-5p, which can inhibit the differentiation of Th1 and Th17 cells.Given the anti-inflammatory and immunosuppressive effects of exosomes, this paper reviewed the studies on ocular surface inflammation and immune-related diseases such as corneal injury, mucopolysaccharide storage disease, dry eye, Sj?gren syndrome and ocular graft-versus-host disease.