Abstract: Objective  To evaluate the immunoprotective activity of the Egrecombinant ferritin and Egrecombinant mMDH proteins in mice.  Methods  Thirty ICR mice were divided into 3 groups and immunized by injection of adjuvantemulsified rEgferritin, rEgmMDH and PBS, respectively, in multiple spots at back, for 3 times with an interval of 2 wk. Two weeks after the last immunization, the mice of the 3 groups were infected intraperitoneally with 0.1 ml suspension containing about 1 500 Echinococcus granulosus (Eg)  protoscoleces. The mice were sacrificed 22 wk after infection and the Eg cysts were collected and measured. Spleens were taken for detecting CD4⁺ T cells and CD8⁺ T cells and ratio calculated.  Results   Eg cysts were found in 30% (3/10) of the mice in the rEgferritin group with 5 cysts altogether; cysts were received in all the mice in the rEgmMDH group with 118 cysts totally; and cysts were found in 7 of 9 mice in the PBS control with 35 cysts totally. The mice in the rEgferritin group showed an 84.7% protection but revealed no protection in the rEgmMDH group. The CD4⁺ T cells were significantly higher in the rEgferritin group than the control, but no statistical difference was found in CD8⁺ T cells and CD4⁺/CD8⁺ ratio between the 2 groups. There was no considerable change in the T cells and ratio in the rEgmMDH group compared to the control.  Conclusion  The Egrecombinant ferritin can inhibit the growth of Eg while the Egrecombinant mMDH seems promoting its growth in mice.

Key words: Echinococcus granulosus, Recombinant ferritin, Recombinant mitochondrial malate dehydrogenase, Immune protection