Immunogenic characterization of the chimeric surface antigen 1 and 2 (SAG1/2) of Toxoplasma gondii expressed in the yeast Pichia pastoris

Lau, Y. L.; Thiruvengadam, G.; Lee, W. W.; Fong, M. Y. (2011) Immunogenic characterization of the chimeric surface antigen 1 and 2 (SAG1/2) of Toxoplasma gondii expressed in the yeast Pichia pastoris. Parasitology Research, 109 (3). pp. 871-878. ISSN 0932-0113

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    Abstract

    In this study, we successfully expressed a chimerical surface antigen 1 and 2 (SAG1/2) of Toxoplasma gondii in Pichia pastoris. Eighty human serum samples, including 60 from confirmed cases of toxoplasmosis, were tested against the purified recombinant SAG1/2 in Western blots. Results of Western blots targeted at Toxoplasma IgG and IgM showed that the recombinant SAG1/2 reacted with all sera from the toxoplasmosis cases but none with the Toxoplasma-negative serum samples. These results showed that the P. pastoris-derived recombinant SAG1/2 was sensitive and specific and suitable for use as antigen for detecting anti-Toxoplasma antibodies. To further investigate the immunological characteristic of the recombinant protein, the recombinant SAG1/2 was injected subcutaneously into BALB/c mice, and their serum was tested against total protein lysate of T. gondii. Mice immunized with the recombinant SAG1/2 reacted specifically with the native SAG1 and SAG2 of T. gondii. Significant proliferation of splenocytes stimulated with tachyzoite total protein lysate was observed in vaccinated BALB/c mice but not in those from negative control mice. Specific production of IFN-gamma, the Th1-type cytokines, was also found in stimulated splenocytes from vaccinated mice. These results show that the chimeric protein recombinant SAG1/2 can elicit a Th1-associated protection against T. gondii infections in mice. Finally, vaccinated mice were significantly protected against lethal challenge with live T. gondii RH strain tachyzoites (P < 0.005), and their survival time increased significantly compared to the negative control.

    Item Type: Article
    Journal or Publication Title: Parasitology Research
    Additional Information: Lau, Yee Ling Thiruvengadam, Girija Lee, Wei Wei Fong, Mun Yik
    Uncontrolled Keywords: Parasitology(Medical Parasitology),Diagnostics(Molecular Diagnosis and Recombinant Antigens),Virology(Molecular Characterisation and Epidemiology)
    Subjects: R Medicine
    Divisions: Faculty of Medicine
    Depositing User: Prof. Dr. Mun Yik Fong
    Date Deposited: 22 Feb 2012 15:41
    Last Modified: 22 Feb 2012 15:41
    URI: http://eprints.um.edu.my/id/eprint/2730

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