Abstract: 　Objective To observe the change of six cytokines in mice infected with Echinococcus multilocularis as part of the study on immunological mechanism in the infection. Methods Mice were infected by abdominal inoculation of echinococcus protoscoleces. The change of serum level of the cytokines IL-2、IFN-γ、TNF-α、IL-4、 IL-5 and IL-10 was determined by ELISA during the infection which lasted for 260 d. Results Compared with uninfected control, the levels of the cytokines all significantly increased in the 260 d. The level of IL-2 reached a peak after 80 d post-infection (p.i.), then decreased quickly after 140 d p.i., High level of TNF-α was detected after 40 d, compared to uninfected control, reached a peak at 100 d p.i., and decreased quickly after 140 d. The level of IFN-γ reached a peak after 80 d p.i., and decreased slowly after 140 d p.i., The levels of IL-4, IL-5 and IL-10 remained lower before 80 d, and increased sharply after 100 days. The levels of IL-4 and IL-10 reached peaks at 100 d p.i., and that of IL-5 at 140 d p.i. Conclusion The data suggest that the induction of Th2 antibody-mediated immunity (AMI) with a parallel expansion of Th1 cell-mediated inflammatory (CMI) responses are important mechanism of the host in defending against the metacestodes. Th1 CMI plays an important role at the early stage of infection, and Th2 AMI is important in the later stage of infection.

Key words: Echinococcus multilocularis, Kunming mice, Cytokines