MIC3, a novel cross-protective antigen expressed in Toxoplasma gondii and Neospora caninum
MIC3, a novel cross-protective antigen expressed in Toxoplasma gondii and Neospora caninum
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MIC3，一种在弓形虫和犬新孢子虫中表达的新型交叉保护抗原
DOI：
10.1007/s00436-015-4609-6
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发表时间：
2015-10-01
影响因子：
2
通讯作者：
Liu, Qun
中科院分区：
文献类型：
--
作者：
Yang, Daoyu;Liu, Jing;Liu, Qun
MIC 3是弓形虫和犬新孢子虫表达的一种重要的粘附分子，在弓形虫的侵袭过程中起重要作用。在我们的研究中，我们发现重组TgMIC 3（rTgMIC 3）被T.弓形虫反应性血清和抗N.犬的抗TgMIC 3多克隆抗体与N.免疫印迹法和免疫荧光法（IFA）检测犬血清中的DNA含量。这些结果表明，MIC 3是一种新的交叉反应性抗原表达在N。caninum和T.刚地。为了研究TgMIC 3的免疫保护作用，我们构建了真核表达载体pcDNA3.1-TgMIC 3，脂质体法转染HEK 293 T细胞，Western blot和IFA检测了TgMIC 3在HEK 293 T细胞中的表达。然后用重组TgMIC 3蛋白、pcDNA3.1-TgMIC 3或双苗免疫BALB/c小鼠。用T. gondii RH或N.最后一次免疫后14天的犬Nc-1速殖子。T.记录感染鼠脑内寄生虫负荷。使用实时PCR测量感染后30天的犬感染小鼠。结果表明，用基于TgMIC 3的疫苗免疫的小鼠引发高抗体滴度。经寄生虫攻击后，pcDNA-TgMIC 3免疫的小鼠在感染T.弓形虫速殖子和较低的寄生虫负荷，在小鼠的大脑中攻击与N。犬速殖子这些结果表明TgMIC 3是在T. gondii和N.犬，并可以引起一些保护免受弓形虫病和新孢子虫病。
Microneme protein 3 (MIC3) is an important adhesion molecule expressed by Toxoplasma gondii and Neospora caninum that plays a crucial role in invasion. In our study, we found that recombinant TgMIC3 (rTgMIC3) was recognized by both T. gondii-reactive sera and hyper-immune serum against N. caninum. Polyclonal antibodies against TgMIC3 reacted with N. caninum by western blot and immunofluorescence assay (IFA). These results indicate that MIC3 is a novel cross-reactive antigen expressed in N. caninum and T. gondii. To evaluate the immune-protective effect of TgMIC3, we created the eukaryotic expression vector pcDNA3.1-TgMIC3, transfected this vector into HEK293T cells by lipofection, and evaluated TgMIC3 expression in HEK293T cells using western blot and IFA. Then, groups of BALB/c mice were immunized with recombinant TgMIC3 protein, pcDNA3.1-TgMIC3, or two-vaccine immunization. The mice were challenged with T. gondii RH or N. caninum Nc-1 tachyzoites 14 days after the final immunization. The survival time of T. gondii-infected mice was recorded, and the parasite burden in the brain of N. caninum-infected mice 30 days post-infection was measured using real-time PCR. The results demonstrated that mice immunized with TgMIC3-based vaccines elicited high antibody titers. After parasitic challenge, mice immunized with pcDNA-TgMIC3 exhibited prolonged survival when infected with T. gondii tachyzoites and a lower parasitic burden in the brains of mice challenged with N. caninum tachyzoites. These results demonstrate that TgMIC3 is a cross-protective antigen expressed in T. gondii and N. caninum and could elicit some protection against toxoplasmosis and neosporosis.