RT Journal Article A1 Guzmán, Mauricio A1 Sabbione, Florencia A1 Gabelloni, María Laura A1 Vanzulli, Silvia A1 Trevani, Analía Silvina A1 Giordano, Mirta Nilda A1 Galletti, Jeremías Gastón T1 Restoring Conjunctival Tolerance by Topical Nuclear Factor–κB Inhibitors Reduces Preservative-Facilitated Allergic Conjunctivitis in Mice JF Investigative Ophthalmology & Visual Science JO Invest. Ophthalmol. Vis. Sci. YR 2014 DO 10.1167/iovs.14-14075 VO 55 IS 9 SP 6116 OP 6126 SN 1552-5783 AB To evaluate the role of nuclear factor–κB (NF-κB) activation in eye drop preservative toxicity and the effect of topical NF-κB inhibitors on preservative-facilitated allergic conjunctivitis. Balb/c mice were instilled ovalbumin (OVA) combined with benzalkonium chloride (BAK) and/or NF-κB inhibitors in both eyes. After immunization, T-cell responses and antigen-induced ocular inflammation were evaluated. Nuclear factor–κB activation and associated inflammatory changes also were assessed in murine eyes and in an epithelial cell line after BAK exposure. Benzalkonium chloride promoted allergic inflammation and leukocyte infiltration of the conjunctiva. Topical NF-κB inhibitors blocked the disruptive effect of BAK on conjunctival immunological tolerance and ameliorated subsequent ocular allergic reactions. In line with these findings, BAK induced NF-κB activation and the secretion of IL-6 and granulocyte-monocyte colony-stimulating factor in an epithelial cell line and in the conjunctiva of instilled mice. In addition, BAK favored major histocompatibility complex (MHC) II expression in cultured epithelial cells in an NF-κB–dependent fashion after interaction with T cells. Benzalkonium chloride triggers conjunctival epithelial NF-κB activation, which seems to mediate some of its immune side effects, such as proinflammatory cytokine release and increased MHC II expression. Breakdown of conjunctival tolerance by BAK favors allergic inflammation, and this effect can be prevented in mice by topical NF-κB inhibitors. These results suggest a new pharmacological target for preservative toxicity and highlight the importance of conjunctival tolerance in ocular surface homeostasis. RD 4/19/2021 UL https://doi.org/10.1167/iovs.14-14075