Shi Tuanyuan, Tao Geru, Bao Guolian, Suo Jingxia, Hao Lili, Fu Yuan, Suo Xun
Department of Animal Parasitology, Institute of Animal Husbandry and Veterinary Medicine, Zhejiang Academy of Agricultural Science Hangzhou, China.
National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University Beijing, China.
Front Microbiol. 2016 May 31;7:807. doi: 10.3389/fmicb.2016.00807. eCollection 2016.
Rabbit coccidiosis, caused by infection of Eimeria spp. is one of the most severe parasitic diseases in rabbits. Eimeria intestinalis is one of the most immunogenic species in rabbit coccidia. Due to the lack of genomic information and unsuccessful in vitro cultivation, genetic manipulation of rabbit coccidia lagged behind other apicomplexan parasites. Using regulatory sequences from E. tenella, we obtained a transgenic line of E. intestinalis expressing yellow fluorescent protein (YFP). YFP was continuously expressed throughout the whole life cycle. Morphological features of E. intestinalis in different developmental stages were dynamically observed with the transgenic line. Some important features in the endogenous development stages were observed. Trophozoites were found as early as 4 h post inoculation. Two types of schizonts and merozoites were observed in first three of the four schizogonies. Beside jejunum and ileum, gametogony stage and oocysts were also found in the duodenum and vermiform appendix. In addition, the transgenic strain was highly immunogenic but less pathogenic than the wild type. Considering the high immunogenicity of E. intestinalis and amenability to transfection with foreign genes, transgenic E. intestinalis could be a promising oral eukaryotic vaccine vector.
兔球虫病由艾美耳属原虫感染引起，是家兔最严重的寄生虫病之一。肠艾美耳球虫是兔球虫中免疫原性最强的种类之一。由于缺乏基因组信息且体外培养未成功，兔球虫的基因操作落后于其他顶复门寄生虫。利用柔嫩艾美耳球虫的调控序列，我们获得了表达黄色荧光蛋白（YFP）的肠艾美耳球虫转基因系。YFP在整个生命周期中持续表达。利用该转基因系动态观察了肠艾美耳球虫不同发育阶段的形态特征。观察到了内生发育阶段的一些重要特征。接种后4小时就发现了滋养体。在四个裂殖生殖阶段的前三个阶段观察到了两种类型的裂殖体和裂殖子。除空肠和回肠外，十二指肠和阑尾也发现了配子生殖阶段和卵囊。此外，转基因株具有高度免疫原性，但致病性低于野生型。考虑到肠艾美耳球虫的高免疫原性和对外源基因转染的易感性，转基因肠艾美耳球虫可能是一种有前途的口服真核疫苗载体。
