Abstract: Objective To study the immunomodulating mechanisms of imiquimod. Methods BALB/c mice were fed with imiquimod(30 mg/kg). After 0.5, 1, 2, 4 hours, serum concentrations of IFN-α, IL-12, IFN-γ, IL-4 were measured by ELISA. The spleen cells of the mice were incubated with 0.25 μg/mL of ConA. IFN-γ and IL-4 were detected by ELISA in the supernatant. Results IL-12 and IFN-α could be induced by imiquimod in vivo. Serum levels of IL-12 and IFN-α peaked in 2 hours after feeding with imiquimod. Serum IFN-γ and IL-4 seemed not to be induced significantly by imiquimod. In vitro, expression of IFN-γ and IL-12 in spleen cells taken from mice fed with imiquimod was enhanced by co-incubation with 0.25 μg/mL ConA. Conclusions Imiquimod could induce the pro-inflammatory cytokine secretion and promote the acquired immunity in BALB/c mice.

Key words: imiquimod, Interleukin-12, Interleukin-4, Interferon-alpha, Animal testing, alternative