Transfer of a T-helper type 2 clone into conjunctiva induces corneal damage in mice

We established a T-helper Type 2 (Th2) clone-induced conjunctival eosinophilia model by injecting D10.G.4.1 (D10) cells, a murine Th2 clone, and conalbumin, its specific antigen, into conjunctiva of AKR/J mice. Using this model, we investigated the effect of a coinjection of D10 cells and conalbumin into conjunctiva on corneal damage.

Corneal fluorescein staining scores and eosinophil peroxidase (EPO) activity in conjunctiva were measured after coinjection of D10 and conalbumin into conjunctiva, and the effects of cyclosporine A, betamethasone, and anti-interleukin-5 antibody on staining scores and EPO activity were examined.

Coinjection of D10 and conalbumin induced an increase of the corneal fluorescein staining score after 24, 48, and 96 hours and 10 days. EPO activity in conjunctiva increased time-dependently until 24 hours after coinjection. The increase in the staining score followed the time dependent increase in EPO activity. The instillation of cyclosporine A, an inhibitor of cytokine production from T-cells, and betamethasone significantly inhibited the increase in corneal fluorescein score and EPO activity. Intraperitoneal administration of anti-interleukin-5 monoclonal antibody, which inhibits the infiltration of eosinophils into the conjunctiva, completely inhibited the increase in staining score.

The transfer of the Th2 clone into the murine conjunctiva induced corneal damage, which may have been caused by Th2 cell-produced interleukin-5 that mediated the activation of eosinophils.