Abstract: ObjectiveTo explore the mechanism causing the sex differences in experimental autoimmune encephalomyelitis (EAE).MethodsEAE model was established with PLP _139-151 in SJL/J mice. The sex differences of illness state were evaluated by neurologic score, and that of response of peripheral lymphocytes to autologous antigens were detected by methods of MTT and ELISA.ResultsThe onset time of female SJL mice was 15±2.1 days less than that of male ones (22±4.3 days), and the feature of diseases course of female mice was relapse after recovery, but that of male mice was transient. No significant differences were observed in T cell responses and interferon-γ productions between male and female mice (P>0.05). Male mice secreted more interleukin-4 than female mice (P<0.01).ConclusionThe sex differences of EAE in mice are due to peripheral lymphocytes secreting more interleukin-4 in male mice.

Key words: experimental autoimmune encephalomyelitis (EAE), SJL/J mice, sex difference, T cell proliferative response, interferon-γ(IFN-γ), interleukin-4 (IL-4)