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
    Creators:
    1. Lau, Y.L.
    2. Thiruvengadam, G.
    3. Lee, W.W.
    4. Fong, M.Y.(Department of Parasitology, Faculty of Medicine Building, University of Malaya, 50603 Kuala Lumpur, MALAYSIA)
    Journal or Publication Title: Parasitology Research
    Additional Information: Y. L. Lau (*) :W. W. Lee : M. Y. Fong Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia e-mail: lauyeeling@um.edu.my
    Uncontrolled Keywords: Parasitology
    Subjects: R Medicine
    Divisions: Faculty of Medicine
    Depositing User: Fong Mun Yik
    Date Deposited: 11 Jun 2012 11:58
    Last Modified: 11 Jun 2012 11:58
    URI: http://eprints.um.edu.my/id/eprint/3238

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