[Immunosuppressive effect of cholera toxin B on allergic conjunctivitis model in the guinea pig]

To investigate the immunosuppressive effects of mucosal immune therapy in experimental allergic conjunctivitis.

We used 11 white Hartrey guinea pigs divided into two groups. Six animals (treated group) received pretreatment with topical instillation of cholera toxin B (4 micrograms/30 ml) and ovalbumin (10 micrograms/30 ml). The other group of 5 animals served as control. All the animals received intraabdominal injection of ovalbumin (100 g/ml) and aluminium hydroxide (5 mg/ml) repeated twice 2 weeks apart. Allergic conjunctivitis was induced by topical instillation of ovalbumin solution (5 mg/ml) one week after the above procedure.

Both groups developed palpebral and bulbar edema with hyperemia 30 minutes after instillation. The allergic reaction was significantly less in score in the treated than in control group (Mann Whitney U-test: p < 0.01). The clinical findings subsiced after 6 hours. The treated group showed less eosinophilic infiltration in the conjunctiva and the limbus, particularly in the conjunctival and the limbus, particularly in the conjunctival epithelium, than in control group at 6 and 24 hours.

Pretreatment with topical cholera toxin B and antigen suppresses clinical and histological findings in experimentally induced allergic conjunctivitis.