1. Academic Validation
  2. The role of interleukin-33 in chronic allergic conjunctivitis

The role of interleukin-33 in chronic allergic conjunctivitis

  • Invest Ophthalmol Vis Sci. 2009 Oct;50(10):4646-52. doi: 10.1167/iovs.08-3365.
Akira Matsuda 1 Yoshimichi Okayama Noriko Terai Norihiko Yokoi Nobuyuki Ebihara Hidetoshi Tanioka Satoshi Kawasaki Tsutomu Inatomi Norito Katoh Eiichiro Ueda Junji Hamuro Akira Murakami Shigeru Kinoshita
Affiliations

Affiliation

  • 1 Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan. [email protected]
Abstract

Purpose: The authors discovered a genetic association between the ST2L gene and atopy. The ST2L gene encodes a membrane-bound functional marker for Th2 cells. Recently, a novel Th2 cytokine, interleukin-33 (IL-33), was discovered to be a specific ligand for ST2L. The authors investigated the role of IL-33 in chronic allergic conjunctivitis.

Methods: Immunohistochemical analysis was carried out using giant papillae samples obtained from patients with atopic keratoconjunctivitis. The authors used proinflammatory stimuli to clarify IL-33 mRNA/protein-inducing signals with cultured human conjunctival epithelial cells, fibroblasts, human umbilical vascular endothelial cells, and mast cells. These cells were also used to examine the expression of ST2L (IL-33R). Finally, cultured mast cells were stimulated with recombinant IL-33 (rIL-33) to examine the downstream signals.

Results: The authors found IL-33 protein expression in human vascular endothelial cells in the giant papillae and in the control conjunctivae. IL-33 expression was also observed in conjunctival epithelium of the giant papillae but not in the control conjunctivae. IL-1 beta stimulation upregulated IL-33 mRNA expression in conjunctival fibroblasts. The authors also confirmed mature IL-33 protein expression in ocular resident cells by Western blot analysis. Preferential ST2L expression was observed in human mast cells, and phosphorylation of p38 MAPK and IL-13 mRNA induction was observed in human cultured mast cells after rIL-33 stimulation. Phosphorylation of p38 MAPK was inhibited by soluble ST2 protein.

Conclusions: The IL-33-ST2 signaling cascade plays some roles in the pathophysiology of chronic allergic conjunctivitis through the activation of mast cells.

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