Abstract
Purpose :
Our lab has previously established the mouse model of allergic eye disease (AED), which involves robust eosinophil and T cell recruitment to the conjunctiva, and mimics the severe/chronic form of ocular allergy in humans. However, whether innate lymphoid populations change in the conjunctiva during the progression of this disease has not been addressed and therefore was the purpose the current study.
Methods :
Our model of AED was induced as follows: 8 week-old C57BL/6 female mice were immunized with an i.p. injection of 10 µg OVA in 300 ng pertussis toxin and 1 mg aluminum hydroxide in PBS. After a 14-day rest period, mice were given topical application of 250 µg OVA solution once a day to each eye for 7 days. Lid swelling, tearing, conjunctival chemosis, and conjunctival redness were each scored on a scale of 1 to 3 and then summed. Scoring was done twice a day, at 20 minutes and at 6 hours post-challenge. Conjunctival tissue was collected from AED mice after the final day of challenge, and from naïve mice as our negative control. Tissues were digested using a standard collagenase digestion protocol and dissociated into single cell suspensions. Flow cytometry was then performed on these cells following simultaneous staining for live/dead, CD45, CD3, B220, CD11b, GR-1, Tbet, GATA3 and RORγt.
Results :
Conjunctival cells that stained for CD45+ CD3- B220- CD11b- GR-1- were considered as the general innate lymphoid population profile. Corresponding with increases in clinical scores in the AED setting, the collective number of these cells increased in the conjunctiva by over 5-fold. All three of the innate lymphoid populations within this pool, which included Tbet+, GATA3+ and RORγt+ cells, appeared to increase in the conjunctiva, though by differing amounts.
Conclusions :
We therefore conclude that AED progression is associated with a quantitative increase in the innate lymphoid population in the conjunctiva. Future studies will focus on the functional roles of these cells in AED pathobiology, as differences in cell increases can be seen among the innate lymphoid subset populations.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.