Aims/Background: To investigate how systemic overexpression of IL-4, IL-5 and IFN-γ affects the severity of experimental conjunctivitis (EC) in mice.
Methods: We electroporated the tibialis anterior muscle of naive BALB/c mice with IL-4, IL-5, IFN-γ or a control gene and then harvested the mice blood and conjunctivas to measure eosinophil content in these tissues. To evaluate the effects of cytokine gene electroporation on the early phase reaction (EPR), cytokine gene-electroporated ragweed (RW)-immunized mice were intravenously injected with Evans blue (EB) and then challenged them with RW in eye drops. Thirty minutes later, we harvested their conjunctivas to extract EB and evaluate the EPR. Additionally, 24 hours after RW challenge, conjunctivas were harvested from cytokine gene-electroporated RW-immunized mice, which had not received intravenous injection of EB, to measure conjunctival eosinophilia.
Results: Significantly more eosinophils were detected in the blood and conjunctivas of IL-5-electroporated mice in which EC was not induced. The intensity of the EPR was significantly greater in IFN-γ-electroporated mice. Significantly greater eosinophil infiltration was seen in the conjunctivas of IL-5-electroporated EC-developing mice.
Conclusions: It appears that systemic IL-5 and IFN-γ play different roles in the development of EC.