Establishment of T-helper type 2 clone-induced eosinophilia in mouse conjunctiva

Eosinophil infiltration is one of the aspects of the inflammatory response to an allergen. The aim of this study was to establish T-helper type-2 (Th2)-induced conjunctival eosinophilia in mice to evaluate the effect of anti-allergic drugs. Th2 clone, D10.G4.1. (D10) with its specific antigen, conalbumin was coinjected into conjunctival tissue in mice. At 3-6 hr after D10 injection, eosinophil and neutrophil recruitment into conjunctival tissue was observed. Cellular infiltration into conjunctival tissue reached a maximum level between 24-48 hr after D10 injection. The number of eosinophils which infiltrated after 24 hr was dose dependent on T cell injection titer from 1 x 10(4), 1 x 10(5) to 1 x 10(6) cells site(-1). The ratio of eosinophils to neutrophils at 24 hr after D10 cell (1 x 10(5) cells site(-1)) injection was about 9 to 1. The eosinophil infiltration into conjunctival tissue was significantly reduced by the intraperitoneal administration of anti-IL-5 monoclonal antibody (100 mu g animal(-1)). Anti-IL-4 monoclonal antibody (500 mu g animal 1) partially inhibited eosinophilia. The combined inhibitory effect of anti-IL-4 and anti-IL-5 monoclonal antibodies was larger than the inhibitory effect of anti-IL-5 monoclonal antibody alone. In conclusion, a Th2-induced mouse conjunctival eosinophilia model was established in which D10 activation results in IL-4 and IL-5 release. These cytokines elicit eosiniophil infiltration. This response shows that the model will be effective for screening candidates of anti-allergic drugs. (C) 1999 Academic Press.