en Molecular Immunology & Vaccines Molecular Immunology & Vaccines مقاله کامل Full Length/Original Article <p><strong>BBackground</strong>: We have previously reported that immunization with GRA 2 antigen of <em>Toxoplasma gondii </em>induces protective immunity in CBA /J (H2k) and BALB/c mice (H2d). We aimed to examine whether immunization of a distinct strain of rodent with recombinant dense granule antigens (GRA2) combined with monophosphorryl lipid A (MPL) adjuvant elicits protective immune response against <em>T. gondii.</em> <strong>Methods</strong>: C57BL/6 (H2b haplotype) mice were immunized with GRA 2, formulated in MPL adjuvant. <strong>Results</strong>: Strong humoral response, predominantly of IgG1 subclass and cellular response, IFN-&gamma;, was detected at three weeks post immunization. Mice immunized with GRA 2 had significantly (<em>p </em>< 0.01) fewer brain cysts than those in the adjuvant group, upon challenge infection. Despite the production of a strong antibody response, IFN-&gamma; production and brain cyst reduction were not significant when the immunized mice were infected four months after the immunization. <strong>Conclusions</strong>: We can conclude that GRA2 immunization partially protects against <em>T. gondii</em> infection in C57BL/6 mice, though the potency and longevity of this antigen as a standalone vaccine may vary in distinct genetic backgrounds. This observation further emphasizes the utility of GRA 2 for incorporation into a multi-antigenic vaccine against <em>T. gondii</em>.</p> Immunization, GRA2, Toxoplasma, MPL 22 32 http://ibj.pasteur.ac.ir/browse.php?a_code=A-10-1-672&slc_lang=en&sid=1 Jalal Babaie No Molecular Parasitology Lab., Department of Parasitology, Pasteur Institute of Iran, Tehran, Iran Samira Amiri No Molecular Parasitology Lab., Department of Parasitology, Pasteur Institute of Iran, Tehran, Iran Robab Homayoun No Molecular Parasitology Lab., Department of Parasitology, Pasteur Institute of Iran, Tehran, Iran Ebrahim Azimi No Molecular Parasitology Lab., Department of Parasitology, Pasteur Institute of Iran, Tehran, Iran Reyhaneh Mohabati No Molecular Parasitology Lab., Department of Parasitology, Pasteur Institute of Iran, Tehran, Iran Mahboubeh Berizi No Molecular Parasitology Lab., Department of Parasitology, Pasteur Institute of Iran, Tehran, Iran M. Reza Sadaie No NovoMed Consulting, Silver Spring, Maryland, USA Majid Golkar Yes Molecular Parasitology Lab., Department of Parasitology, Pasteur Institute of Iran, Tehran, Iran