Wang Guanbo, Efstratiou Artemis, Adjou Moumouni Paul Franck, Liu Mingming, Jirapattharasate Charoonluk, Guo Huanping, Gao Yang, Cao Shinuo, Suzuki Hiroshi, Igarashi Ikuo, Xuan Xuenan
National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 427 Maduan Street, Harbin 150001, China.
Exp Parasitol. 2017 Jan;172:5-11. doi: 10.1016/j.exppara.2016.11.001. Epub 2016 Nov 19.
In this study, we evaluated the protective effect of recombinant Babesia microti apical membrane protein 1 (rBmAMA1) and rhoptry neck protein 2 (rBmRON2) against B. microti infection using a hamster model. The genes encoding the predicted domains I and II of BmAMA1 and the gene encoding the predicted transmembrane regions 2 and 3 of BmRON2 were expressed as His fusion recombinant proteins in Escherichia coli. Three groups with 5 hamsters in each group were immunized with rBmAMA1, rBmRON2 and rBmAMA1+rBmRON2, then challenged with B. microti. The result showed that only the group immunized with rBmAMA1+rBmRON2 exhibited limited protection against B. microti challenge infection, characterized by significant decreased of parasitemia and higher hematocrit values from day 6-10 post challenge infection. However, there was no significant difference in the groups immunized with rBmAMA1 or rBmRON2 alone. The absence of a significant difference in the total amount of antibodies against rBmAMA1 and rBmRON2 between the group immunized with single and combined proteins. This result suggests that the protection cannot be solely attributed to the quantity of antibodies produced, but also to their ability to target important epitopes from both antigens. These results suggest that combined immunization with rBmAMA1 and rBmRON2 is a promising strategy against B. microti.
在本研究中，我们使用仓鼠模型评估了重组微小巴贝斯虫顶端膜蛋白1（rBmAMA1）和棒状体颈部蛋白2（rBmRON2）对微小巴贝斯虫感染的保护作用。编码BmAMA1预测结构域I和II的基因以及编码BmRON2预测跨膜区域2和3的基因在大肠杆菌中表达为His融合重组蛋白。将每组5只仓鼠的三组分别用rBmAMA1、rBmRON2和rBmAMA1+rBmRON2免疫，然后用微小巴贝斯虫进行攻击。结果显示，只有用rBmAMA1+rBmRON2免疫的组对微小巴贝斯虫攻击感染表现出有限的保护作用，其特征是攻击感染后第6至10天虫血症显著降低，血细胞比容值更高。然而，单独用rBmAMA1或rBmRON2免疫的组之间没有显著差异。单独和联合蛋白免疫组之间针对rBmAMA1和rBmRON2的抗体总量没有显著差异。这一结果表明，保护作用不能仅仅归因于产生的抗体数量，还归因于它们靶向两种抗原重要表位的能力。这些结果表明，rBmAMA1和rBmRON2联合免疫是对抗微小巴贝斯虫的一种有前景的策略。
