Echinococcus Granulosus Recombinant Gst Protective Immunity And Its Immune Mechanism In Mice

Objective To obtain Echinococcus granulosus recombinant GST (rEg.GST) and test its immune protective efficiency and immune mechanism in mice immunized with rEg.GST. This could provide a kind of valuable vaccine to control cystic echinococcosis. Methods (1) Purified of EgGST/pET-28a.①Expressed and purified rEgGST by His-bind affinity chromatography with Ni2+. (2) Immune protection and immune mechanism against challenge infection with Echinococcus granulosus protoscoleces in mice induced with rEgGST.①Observation on protection by immunization with rEgGST against Eg protoscoleces.②Change of splenocyte subsets in mice immunized with rEgGST against Eg protoscoleces.③Change of splenocyte lymphokines in mice immunized with rEgGST against Eg protoscoleces and the proliferation activity of spleen T lymphocytes induced by ConA or rEgGST was detected by MTT assay. Results (1) Purified rEgGST and SDS-PAGE analysis showed 28KDa molecular weight of recombinant protein. (2)①rEgGST can induce 89.39% immune protective efficiency in mice against the challenge infection and induce mice to produce high level of IgG,IgG2a and IgG3, the low level of IgG1 and IgE, IgG2b increased before challenge with protoscoleces, decreased after challenge, it suggested that IgG,IgG2a,IgG2b and IgG3 could participate in the mechanism of protective immune response.②After mice inoculated with rEgGST was challenged, CD4+ subsets obviously enhanced and CD8+ subsets lightly rised. It hinted that CD4+ and CD8+ subsets could enlist the protective immune mechanism; after challenge with Eg protoscoleces CD25+ subsets lightly rised.③After challenge, rEgGST induced mice to product the high level of IL-2, IFN-γand TNF-α, it indicated that rEgGST induced Th1 type immune reaction. As demonstrated by MTT assay, the proliferation activity of splenic T lymphocyte in rEgGST group was higher than that in PBS group (P<0.01). Conclusions (1) The recombinant plasmid EgGST/pET-28a was successfully be expressed and purified. (2) We observate that rEgGST can induce 89.39% immune protective efficiency. (3) We may conclude that protection against Echinococcus granulosus protoscoleces induced with rEgGST was associated with hunoral and Th1 cellular responses.