Production and immunoanalytical application of 32 monoclonal antibodies against metacestode somatic antigens of Echinococcus multilocularis.

Alveolar echinococcosis is a rare but potentially fatal disease. Immunodiagnosis based on antibodies or antigens plays an important role in its diagnosis. In this study, metacestode somatic antigens of Echinococcus multilocularis were used to immunize BALB/c mice, and hybridomas were formed by cell fusion. Making use of the inherent effect of monoclonal antibody techniques to isolate different epitopes, we obtained a repertoire of 32 monoclonal antibodies against the metacestode somatic antigens. These monoclonal antibodies were used to investigate the specificity and localization of the metacestode antigens by enzyme-linked immunosorbent assay and immunohistochemistry, respectively. Nine antibodies specifically reacted with E. multilocularis, while 14 and ten cross-reacted with Echinococcus granulosus and Taenia saginata, respectively. Twenty-five antibodies stained the laminated layer. Eight reacted with the tegument of the protoscolex. Fourteen antibodies recognized the germinal layer. Most of the monoclonal antibodies can react with the antigen Em2. One antibody can react with antigen Em2 and Em10. One antibody that cross-reacted with T. saginata stained the germinal layer and protoscolex, especially its hooklets and suckers, but could not react with Em2 and Em10 antigens. It detected protein bands at 26 and 52 kDa. Two E. multilocularis-specific monoclonal antibodies stained both the germinal and laminated layers and could be used not only to purify specific antigens but also for immunohistochemical studies of E. multilocularis. In summary, these 32 monoclonal antibodies could have potential applications as useful tools in further studies of E. multilocularis antigen profiles.

[Production of a monoclonal antibody specific to protoscolex of Echinococcus multilocularis].

OBJECTIVE: To prepare monoclonal antibody (McAb) specific to protoscolex of Echinococcus multilocularis. METHODS: BALB/c mice were immunized with crude antigen derived from E. multilocularis metacestodes. Spleen cells from immunized BALB/c mice were fused with SP2/0 myeloma cells by using hybridoma technique. ELISA and immunohistochemical staining were used to select hybridomas that secreted McAb P325 which especially against protoscolex. The number of metaphase chromosomes of hybridoma cells was counted. Characteristics of McAb P325 were identified by ELISA and immunohistochemical staining. RESULTS: One hybridoma cell clone secreting McAb against protoscolex was obtained. The number of metaphase chromosomes found in hybridoma cells was 98, which showed the characteristics of their parents. Immunohistochemical analysis showed that McAb P325 demonstrated binding activity to the germinal layer and protoscolex of E. multilocularis, especially to the hooklets and suckers, while did not bind with E. granulosus metacestodes and Cysticercus tenuicollis. CONCLUSION: The McAb is a valuable tool for immunohistochemical analysis, cell classification of E. multilocularis protoscolex, and study of specific antigen.