Abstract: Objectives To establish an experimental model for Th1 type shifting and meet the requirements of studying on the mechanisms of some immunomodulators.Methods The levels of cytokines, IL-12, IFN-γ and IL-4, produced in vitro by spleen cells of the BALB/c mice were detected by using ELISA.Spleen cells of the BALB/c mice were incubated under the following conditions: with different concentrations of T cell mitogen ConA (1 mg/mL, 0.5 mg/mL, 0.25 mg/mL, 0.125 mg/mL), mononuclear phagocyte system activator LPS (50 mg/mL, 5 mg/mL, 0.5 mg/mL) or LPS (50 mg/mL, 5 mg/mL, 0.5 mg/mL) combined with 0.25 mg/mL ConA.Results LPS could induce the production of IL-12 from spleen cells.The lowest concentration that ConA could induce the measurable production of IFN-γ from spleen cells was 0.25 mg/mL.When different concentrations of LPS were combined with 0.25 mg/mL ConA, LPS could accelerate the production of IFN-γ and positively with that of IL-12.Conclusion LPS combined with ConA can induce the activation of spleen cells from mice towards Th1 type response.

Key words: Interleukin-12, Interleukin-4, Interferon type Ⅱ, Lipopolysa cchrides, Concanavalin A