Subcutaneous IL-18 administration does not inhibit laser CNV in mice

Abstract

Purpose : Choroidal neovascularization (CNV) is a leading cause of legal blindness among the elderly. Activation of inflammatory process underlies development and progression of CNV. We previously demonstrated that intravitreous administration of the inflammatory cytokine IL-18 did not affect CNV. Anti-angiogenic activity was previously reported by subcutaneous administration of IL-18 manufactured by GlaxoSmithKline to mice, a different source and route from our prior studies. Here, we retested the effects of IL-18 on CNV using recombinant IL-18 from GlaxoSmithKline delivered by subcutaneous injection.

Methods : IL-18 was obtained from GlaxoSmithKline (the same lot as previously reported to exhibit anti-angiogenic activity). To induced CNV model, laser photocoagulation (532nm, 180mW, 0.1sec) was performed in male C57BL/6J mice. Subcutaneous injections of IL-18 or vehicle control were performed before and after laser treatment, in four dosing schemes. Seven days after laser treatment, CNV formation in the laser-burn area was visualized by fluorescein-conjugated isolectin B4, and analyzed by confocal microscopy.

Results : None of four administration protocols changed the size of CNV legions, compared with their vehicle controls.

Conclusions : We did not confirm the anti-angiogenic activity of IL-18, in laser-induced CNV mice.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.