Comparative study on the immunogenicity between recombinant MS-Sj26GST vaccine and recombinant BCG-Sj26GST vaccine in schistosoma japonicum

Abstract

The BALB/c mice were immunized with rMS-Sj26GST and rBCG-Sj26GST vaccine in Schistosoma japonicum by subcutaneous injection. After they were immunized for 8 weeks, the eye-balls were removed to get blood and macrophages of abdominal cavity and spleen cells were harvested. The lymphocytic stimulating index (SI) was used to measure the cellular proliferating ability and NO release was used to measure the phagocytic activity of the macrophages. By using ELISA kit, the levels of interleukin-2 (IL-2) and interferon-γ (IFN-γ) in serum and the splenic lymphocytic cultured supernatant were detected. The results showed that after the mice were immunized with 10⁶ CFU of rMS-Sj26GST and rBCG-Sj26GST vaccine separately by subcutaneous injection, proliferating ability of splenic lymphocytes in the mice showed no difference (P>0.05), but both were significantly increased as compared with that in the control group (P<0.05); The contents of NO in the intraperitoneal macrophages of rMS-Sj26GST vaccine group were significantly lower than in the control group (P<0.001) and rBCG-Sj26GST vaccine group (P<0.01): The levels of serum IL-2 in the rMS-Sj26GST vaccine group were significantly increased as compared with that in the control group (P<0.001), vector group (P<0.01) and rBCG-Sj26GST vaccine group (P<0.05); The contents of serum IFN-γ in the rMS-Sj26GST vaccine group were significantly increased as compared with that in the control group (P<0.01) and rBCG-Sj26GST vaccine group (P<0.05). The contents of IFN-γ in the cultured supernatant were significantly lower than those of rBCG-Sj26GST vaccine group (P<0.001) but were significantly increased as compared with that in the control group (P<0.01). It was indicated that both vaccines could enhance the immune response of the mice, but rMS-Sj26GST vaccine had stronger immunogenicity than rBCG-Sj26GST vaccine.

Keywords

Schistosoma japonnicum / Mycobacterium smegmatis mc² 155 (MS) / BCG / Vaccine / Immunogenicity

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