Effects of immunosuppressants on concanavalin A-induced interleukin-2 mRNA expression in mouse liver.

Treatment of mice with concanavalin A (Con A) induced interleukin-2 (IL-2) mRNA expression in the liver, which might be a result of Con A-induced T-cell activation. Pretreatment with cyclosporine A (CsA) (50 mg/kg, i.p.) or dexamethasone (DEX) (2.5 mg/kg, i.p.) inhibited the Con A-induced liver injury, as assessed by the plasma alanine aminotransferase level, by 85% and 95%, respectively. CsA inhibited the Con A-induced IL-2 mRNA expression completely, whereas DEX only partially inhibited it. Thus CsA seems to prevent Con A-induced hepatitis mainly by inhibiting T-cell activation. In the case of DEX, rather than by inhibiting Con A-induced T-cell activation, it may prevent Con A-induced hepatitis through other means.