AIM： To analyze the biological role of the surface antigen of Toxoplasma gondii（Tgondii） in development of vaccine. METHODS： The surface antigen of Tgondii （SAG1） was expressed in vitro. The immune response of t...AIM： To analyze the biological role of the surface antigen of Toxoplasma gondii（Tgondii） in development of vaccine. METHODS： The surface antigen of Tgondii （SAG1） was expressed in vitro. The immune response of the host to the antigen was investigated by detection of specific antibody reaction to SAG1 and production of cytokines. Mice were immunized with recombinant SAG1 and challenged with lethal strain of Tgondii RH. The monoclonal antibody to r-SAG1 was prepared and used to study the effects of SAG1 on Tgondii tachyzoites under electromicroscope. RESULTS： The mice immunized with recombinant SAG1 delayed death for 60 h compared to the control group. The recombinant SAG1 induced specific high titer of IgG and IgM antibodies as well as IFN-y, IL-2 and IL-4 cytokines in mice. In contrast, IL-12, IL-6 and TNF-α were undetectable. When T gondii tachyzoites were treated with the monoclonal antibody to r-SAG1, the parasites were gathered together, destroyed, deformed, swollen, and holes and gaps formed on the surface. CONCLUSION： SAG1 may be an excellent vaccine candidate against T gondii. The immune protection induced by SAG1 against Tgondii may be regulated by both hormone- and cell-mediated immune response.展开更多
基金Supported by China Ministry of Human Affairs and Department of Science and Technology of Shandong Province, No. 031050115
文摘AIM： To analyze the biological role of the surface antigen of Toxoplasma gondii（Tgondii） in development of vaccine. METHODS： The surface antigen of Tgondii （SAG1） was expressed in vitro. The immune response of the host to the antigen was investigated by detection of specific antibody reaction to SAG1 and production of cytokines. Mice were immunized with recombinant SAG1 and challenged with lethal strain of Tgondii RH. The monoclonal antibody to r-SAG1 was prepared and used to study the effects of SAG1 on Tgondii tachyzoites under electromicroscope. RESULTS： The mice immunized with recombinant SAG1 delayed death for 60 h compared to the control group. The recombinant SAG1 induced specific high titer of IgG and IgM antibodies as well as IFN-y, IL-2 and IL-4 cytokines in mice. In contrast, IL-12, IL-6 and TNF-α were undetectable. When T gondii tachyzoites were treated with the monoclonal antibody to r-SAG1, the parasites were gathered together, destroyed, deformed, swollen, and holes and gaps formed on the surface. CONCLUSION： SAG1 may be an excellent vaccine candidate against T gondii. The immune protection induced by SAG1 against Tgondii may be regulated by both hormone- and cell-mediated immune response.
