Olopatadine inhibits anti-immunoglobulin E-stimulated conjunctival mast cell upregulation of ICAM-1 expression on conjunctival epithelial cells

Background: Olopatadine is a clinically effective dual-action (antihistamin e/mast cell stabilizer) ophthalmic antiallergic agent. We have previously d emonstrated that olopatadine inhibits tumor necrosis factor alpha (TNF-alph a) release from purified human conjunctival mast cells and that supemates f rom stimulated mast cells upregulate intercellular adhesion molecule 1 (ICA M-1) expression on epithelial cells via TNF-alpha. Objective: To investigate the effect of olopatadine on the TNF-alpha -media ted mast cell upregulation of ICAM-1 expression on conjunctival epithelial cells. Methods: Human conjunctival mast cells and epithelial cells were purified ( > 95%) from cadaveric tissue. Conjunctival mast cells were preincubated wit h three doses (30, 300, or 3,000 muM) of olopatadine or buffer alone for 30 minutes followed by 90-minute challenge with anti-immunoglobulin E (10 mug /mL). The resulting supernates were incubated with conjunctival epithelial cell monolayers for 24 hours along with the following treatments: rTNF-alph a, mast cell supernate + anti-TNF-alpha, recombinant (r)TNF-alpha + anti-TN F-alpha, the three doses of olopatadine, olopatadine supernates, olopatadin e supernates + rTNF-alpha. ICAM-1 expression was measured using flow cytome try. Results: Anti-IgE-stimulated human conjunctival mast cell supernates upregu lated human conjunctival epithelial cell ICAM-1 expression to the same exte nt as rTNF-alpha. ICAM-1 upregulation could be completely blocked with anti -TNF-alpha. Preincubation of conjunctival mast cells with olopatadine signi ficantly blocked the ability of supernates to upregulate ICAM-1 on conjunct ival epithelial cells. ICAM-1 expression could be restored by adding rTNF-a lpha to the olopatadine-preincubated mast cell supernates. Conclusions: Olopatadine is able to significantly decrease the anti-immunog lobulin E mast cell supernate-mediated upregulation of ICAM-1 on human conj unctival epithelial cells in vitro. This seems to be mediated through an ef fect on a TNF-aspecific mechanism.