In December 2011, we reported an autochthonous case of Echinococcus multilocularis infection in a 42-year-old woman in Korea. The diagnosis was based on histopathological findings of the surgically resected liver cyst. In the present study, we evaluated the serological and molecular characteristics of this Korean E. multilocularis case. The patient's serum strongly reacted with affinity-purified native Em18 and recombinant Em18 antigens (specific for E. multilocularis) but negative for recombinant antigen B8/1 (reactive for Echinococcus granulosus). In immunoaffinity chromatography, the serum also strongly reacted with E. multilocularis and only weakly positive for E. granulosus. We determined the whole nucleotide sequence of cox1 (1,608 bp) using the paraffin-embedded cystic tissue which was compared with E. multilocularis isolates from China, Japan, Kazakhstan, Austria, France, and Slovakia. The Korean case showed 99.8-99.9% similarity with isolates from Asia (the highest similarity with an isolate from Sichuan, China), whereas the similarity with European isolates ranged from 99.5 to 99.6%.
Adult ; Animals ; Antibodies, Helminth/*blood ; Antigens, Helminth/genetics/*immunology/metabolism ; Base Sequence ; Echinococcosis, Hepatic/*immunology/parasitology ; Echinococcosis, Pulmonary/diagnosis/genetics/immunology ; Echinococcus granulosus/genetics/immunology ; Echinococcus multilocularis/genetics/*immunology/isolation & purification ; Electron Transport Complex IV/genetics ; Female ; Humans ; Mitochondria/genetics ; Molecular Sequence Data ; Republic of Korea ; Sequence Analysis, DNA

OBJECTIVETo investigate the protective immunity against Echinococcus granulosus in mice immunized with rEg14-3-3.

METHODSICR mice were subcutaneously immunized three times with rEg14-3-3, followed by the challenge with Echinococcus granulosus protoscoleces intraperitoneally and then sacrificed after six months of post-challenge to detect the proliferation of splenocytes by MTT assay, and to measure the secretion of IL-2, IL-4, IL-10, and IFN-γ by ELISA. The rate of reduced hydatid cyst and the levels of IgE, IgG and IgG subclasses in sera were examined.

RESULTSMice vaccinated with rEg14-3-3 and challenged with protoscoleces revealed significant protective immunity of 84.47%. ELISA analysis indicated that the immunized mice generated specific high levels of IgG and the prevailing isotypes of IgG were IgG1 and IgG2a. Splenocytes from mice immunized with rEg14-3-3 showed a significant proliferation response. The secretion of IFN-γ and IL-2 increased significantly in the vaccinated mice whereas there was no significant difference in IL-4 and IL-10 levels between vaccinated and control mice.

CONCLUSIONThe results indicate that the rEg14-3-3 vaccine could induce a high level of protective immunity as a promising vaccine candidate to prevent cystic echinococcosis.

14-3-3 Proteins ; genetics ; metabolism ; Animals ; Blotting, Western ; Cell Proliferation ; Cytokines ; genetics ; metabolism ; Echinococcosis ; prevention & control ; Echinococcus granulosus ; genetics ; metabolism ; Enzyme-Linked Immunosorbent Assay ; Gene Expression Regulation ; physiology ; Mice ; Spleen ; cytology ; Vaccines ; immunology