Wang Guanbo, Yu Longzheng, Efstratiou Artemis, Moumouni Paul Franck Adjou, Liu Mingming, Guo Huanping, Gao Yang, Cao Shinuo, Zhou Mo, Li Jixu, Ringo Aaron Edmond, Xuan Xuenan
National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
Department of Veterinary Medicine, Yanbian University, Yanji, Jilin Province 133002, People's Republic of China.
Acta Parasitol. 2018 Jun 26;63(2):368-374. doi: 10.1515/ap-2018-0042.
In the present study, we have investigated the protective effect of a heterologous prime-boost strategy with priming plasmid DNA followed by recombinant adenovirus, both expressing BmAMA1, against Babesia microti infection. Four groups consisting of 3 hamsters per group were immunized with pBmAMA1/Ad5BmAMA1, pNull/Ad5BmAMA1, pBmAMA1/Ad5Null and pNull/Ad5Null, followed by challenge infection with B. microti. Our results showed that hamsters immunized with plasmid and adenovirus expressing BmAMA1 developed a robust IgG and IgG2a antibody response against BmAMA1, suggesting the DNA vaccine or viral vector vaccine tend to induce a Th1-biased response. Compared to the control hamsters, the hamsters vaccinated either with the prime-boost strategy or one of the two "vaccines" exhibited no significant protection against B. microti challenge. Although a slight difference in terms of parasitemia and hematocrit values at days 14-16 post challenge infection was observed, no other statistical difference was detected. Our results indicate that the prime-boost vaccination strategy of injection of plasmid and adenovirus expressing BmAMA1 is not efficient in protecting against B. microti infection.
在本研究中，我们研究了一种异源初免-加强策略的保护作用，该策略先用表达微小巴贝斯虫（Babesia microti）表面抗原1（BmAMA1）的质粒DNA进行初免，随后用重组腺病毒进行加强免疫。将每组3只仓鼠分为四组，分别用pBmAMA1/Ad5BmAMA1、pNull/Ad5BmAMA1、pBmAMA1/Ad5Null和pNull/Ad5Null进行免疫，随后用微小巴贝斯虫进行攻击感染。我们的结果表明，用表达BmAMA1的质粒和腺病毒免疫的仓鼠产生了针对BmAMA1的强烈IgG和IgG2a抗体反应，这表明DNA疫苗或病毒载体疫苗倾向于诱导以Th1为主的反应。与对照仓鼠相比，采用初免-加强策略或两种“疫苗”之一进行疫苗接种的仓鼠对微小巴贝斯虫攻击没有表现出显著的保护作用。尽管在攻击感染后第14 - 16天观察到寄生虫血症和血细胞比容值存在轻微差异，但未检测到其他统计学差异。我们的结果表明，注射表达BmAMA1的质粒和腺病毒的初免-加强疫苗接种策略在预防微小巴贝斯虫感染方面并不有效。
