Abstract
Purpose:
Natural helper (NH) cells are identified innate lymphocyte population, which respond to a combination of interleukin (IL)-2 and IL-25 or IL-33 to produce large amounts of TH2 cytokines and induce eosinophil infiltration in the lung- and gut-associated lymphoid tissues. We identified NH cells in mouse lacrimal- and conjunctival- tissues obtained from papain-induced conjunctivitis model, in which innate immune system dependent conjunctival eosinophilic infiltration was observed.
Methods:
To made papain-induced conjunctivitis model mice, papain-soaked soft contact lens (2mm diameter) was inserted into the conjunctival sacs of C57/BL6(B6) mice or B6-Rag2 knockout (KO) mice, which lack acquired immune systems, and the eye lids were sutured. 4days after contact lens installation, the eyes were subjected to histological analysis. Flow cytometric analyses were performed using anti-Siglec-F and anti-CCR3 antibodies to quantify infiltrated eosinophils. Spleen, thymus, cervical lymph node, lacrimal gland, and conjunctival tissues obtained from the papain-induced conjunctivitis model mice were subjected to cytometric analysis. At the same time, serum IgE concentration of the mice was quantified.
Results:
We identified the existence of NH cells (Lineage- ST2+ CD25+CD127+Sca1+Thy1+) in the conjunctival- and lacrimal gland -tissues obtained from papain-induced conjunctival model. Papain-induced conjunctivitis model showed comparable degree of eosinophil infiltration in the conjunctivae of Rag2 KO mice compared to those of wild-type mice. (53 ± 34 versus 73 ± 44, mean number of eosinophil ± SD per slides, n = 6 , P> 0.05 by Mann-Whitney’s U test ) Siglec-F+CCR3+ eosinophils were increased in the conjunctivae of papain-induced conjunctivitis model compared to naïve conjunctivae. (0.126 versus 0.0679, the ratio of Siglec-F+CCR3+/CD45+ cells). Total IgE concentrations were unchanged during conjunctivitis induction using papain-soaked contact lens.
Conclusions:
We made innate immune system-dependent conjunctivitis model with papain-soaked soft contact lenses. NH cells were identified in the conjunctival tissue and in the lacrimal tissue of the papain-induced conjunctivitis model.
Keywords: 475 conjunctivitis