Abstract
Purpose :
We previously reported the essential roles of IL-33 in ragweed(RW)-induced experimental allergic conjunctivitis (EAC), identified existence of group 2 innate lymphoid cells (ILC2s) in lacrimal glands (LG) and effects of IL-33 with LG excision (ARVO2014, 2016). In this study, we further examined the roles of IL-33 in RW-EAC models with LG excision.
Methods :
LG excision was performed unilaterally on 8-week-old female BALB/c-IL-33 deficient and BALB/c wild-type mice. The mice were sensitized with RW in alum, and then challenged 4 times with RW eye drops. Twenty minutes after the last eye-drop challenge, the EAC was evaluated using the scores for chemosis, redness, lid edema, tearing, discharge, and the number of scratching behaviors was counted for 20 minutes.
24 hours after the last challenge, the eyeballs were collected for histological analyses.
Results :
Significant reduction of the numbers of scratching behaviors was observed in the RW-EAC models using IL-33 deficient mice compared to wild type mice. Histological examination revealed augmented epithelial cell defects and neutrophil predominant inflammatory cell infiltration in the ocular surface of the LG-excised RW-EAC models using IL-33 deficient mice compared to those of wild-type mice.
Conclusions :
The existence of IL-33 in mouse ocular surface caused ocular irritation and induced scratching behaviors in RW-EAC models. On the other hand, IL-33 may contribute to protect eye surface from neutrophil predominant ocular surface inflammation in RW-EAC models with LG excision.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.