Purpose To investigate cytokine mRNA expression and the influence of acyclovir and tetrandrine on that expression in the corneas of mice infected with herpes simplex virus type 1 (HSV-1).

Methods Male BALB/c mice were infected in the right cornea with HSV-1. The corneas were harvested from control normal mice and from untreated, acyclovir-treated and tetrandrine-treated mice 14 days after infection. The infected corneas of each group were divided into inflamed and uninflamed depending on clinical observation. After total mRNA extraction from the corneas, gene expression of interleukin 1β (IL-1β), IL-6, tumour necrosis factor α (TNF-α) and transforming growth factor (β (TGF-β) was analysed by reverse transcription polymerase chain reaction.

Results No mRNA expression of the cytokines was found in normal corneas. IL-β and TNF-α mRNA was seen in inflamed corneas, while mRNA expression of IL-6 and relatively weaker TGF-β mRNA expression were found both in inflamed corneas and in infected but uninflamed corneas treated with acyclovir. TNF-α mRNA was present in the uninflamed corneas of tetrandrine-treated mice. No influence of either agent was found on TGF-β gene expression.

Conclusions The results suggest that local IL-1β and TNF-α gene expression is required for corneal inflammation, whereas IL-6 and TGF-β may exert antiviral and inflammation regulatory activities in HSV corneal infection.