Topical Application Of Benzalkonium Chloride Increases CD4+T Cell-mediated Inflammation In Ocular Surface Of Mice

PURPOSE.To determine if topical application of Benzalkonium Chloride(BAC)induce CD4+T cell-mediated immunocyte and ocular surface damage in mice.METHODS.Topical treatment of BAC was applied in C57BL/6 mice.Oregon-green-dextran(OGD)staining was performed to assess corneal epithelial barrier function.PAS staining was used to quantify conjunctival goblet cells.The phenol red cotton test was used to measure tear production.Immunohistochemical staining was used to detect the infiltration of CD4+T cells and mast cells.Quantitative(q)RT-PCR assay and ELISA assay were used to measure the gene expressions or protein levels of IFN-γ,IL-17,IL-13,IL-4 and IL-5 in conjunctiva and cervical lymph node(CLN).Adoptive transplantation of CD4+ T cells isolated from the mice after treatment of BAC into the nude mice was conducted to identify the function of CD4+T cell-mediated inflammation.RESULTS.Topical administration of BAC induced corneal barrier dysfunction,goblet cell loss,and decrease of tear production.BAC also resulted in infiltration of CD4+T cells and mast cells in conjunctiva,and increased gene expressions and protein levels of IFN-γ,IL-17,IL-13,IL-4 and IL-5 in conjunctiva and cervical lymph nodes.Furthermore,adoptive transplantation of CD4+T cells into nude mice increased immunocyte and CD4+T cell-mediated inflammation,and caused ocular surface damage.CONCLUSIONS.Topical application of BAC induced ocular surface damage through CD4+T cell-mediated inflammation.