Department of Parasitology, Southern Medical University, Guangzhou, Guangdong 510515, People's Republic of China.
Vaccine. 2011 Mar 24;29(15):2742-8. doi: 10.1016/j.vaccine.2011.01.089. Epub 2011 Feb 11.
The Toxoplasma gondii nucleoside triphosphate hydrolase (TgNTPase) has apyrase activity, degrading ATP to the di- and mono-phosphate forms and may be used by the parasite to salvage purines from the host cell for survival and replication. To study the immune-protective value of TgNTPase-II, BALB/c mice were immunized with a recombinant form of the antigen rTgNTPase-II combined with alum. All immunized mice produced specific anti-rTgNTPase-II immunoglobulins, with high IgG antibody titers and a mixed IgG1/IgG2a response, with predominance of IgG2a production. The cellular immune response was associated with the production of IFN-γ and IL-2 cytokines and the increase of the percentage of CD8+ T cells. Vaccinated mice displayed significant protection against acute infection with the virulent RH strain (P<0.05 in survival rate) and also chronic infection with PRU cyst (62.9% and 57.6% reduction in brain parasite load for rTgNTPase-II+alum and rTgNTPase-II alone vaccinated groups) compared to the non-vaccinated control group. In conclusion, rTgNTPase-II elicits a strong specific Th1 immune response providing partial protection against both T. gondii acute and chronic infection.
刚地弓形虫核苷三磷酸水解酶（TgNTPase）具有apyrase 活性，可将 ATP 降解为二磷酸和单磷酸形式，可能被寄生虫用于从宿主细胞中回收嘌呤以维持生存和复制。为了研究 TgNTPase-II 的免疫保护价值，我们用重组抗原 rTgNTPase-II 联合明矾对 BALB/c 小鼠进行了免疫。所有免疫的小鼠均产生了特异性抗 rTgNTPase-II 免疫球蛋白，具有高 IgG 抗体滴度和 IgG1/IgG2a 的混合反应，以 IgG2a 产生为主。细胞免疫反应与 IFN-γ 和 IL-2 细胞因子的产生以及 CD8+T 细胞百分比的增加有关。与未接种疫苗的对照组相比，接种疫苗的小鼠对强毒 RH 株的急性感染（存活率 P<0.05）和 PRU 囊肿的慢性感染显示出显著的保护作用（rTgNTPase-II+明矾和 rTgNTPase-II 单独接种组脑中寄生虫负荷分别减少 62.9%和 57.6%）。总之，rTgNTPase-II 引发了强烈的特异性 Th1 免疫反应，为弓形虫的急性和慢性感染提供了部分保护。
