AUTHOR=Tao Geru , Shi Tuanyuan , Tang Xinming , Duszynski Donald W. , Wang Yunzhou , Li Chao , Suo Jingxia , Tian Xiuling , Liu Xianyong , Suo Xun 

TITLE=Transgenic Eimeria magna Pérard, 1925 Displays Similar Parasitological Properties to the Wild-type Strain and Induces an Exogenous Protein-Specific Immune Response in Rabbits (Oryctolagus cuniculus L.)

JOURNAL=Frontiers in Immunology

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2017.00002

DOI=10.3389/fimmu.2017.00002

ISSN=1664-3224

ABSTRACT=<p>Rabbit coccidiosis causes great economic losses to world rabbitries. Little work has been done considering genetic manipulation on the etiological agents, rabbit <italic>Eimeria</italic> spp. In this study, we constructed a transgenic line of <italic>Eimeria magna</italic> (<italic>EmagER</italic>) expressing enhanced yellow fluorescent protein (EYFP) and red fluorescent protein (RFP) using regulatory sequences of <italic>Eimeria tenella</italic> and <italic>Toxoplasma gondii</italic>. We observed the life cycle of <italic>EmagER</italic> and confirmed that the transgenic parasites express exogenous proteins targeted to different cellular compartments throughout the entire life cycle. EYFP was expressed mainly in the nucleus and RFP both in the nucleus and cytoplasm. Then, coccidia-free, laboratory-reared 40-day-old rabbits were primarily infected with either <italic>EmagER</italic> or wild-type strain oocysts and challenged with the wild-type strain. <italic>EmagER</italic> showed similar reproductivity and immunogenicity to the wild-type strain. Finally, we examined the foreign protein-specific immune response elicited by <italic>EmagER</italic>. Rabbits were immunized with either transgenic or wild-type oocysts. Immune response against parasite-soluble antigen, EYFP and RFP in spleen, and mesenteric lymph nodes were detected by quantitative real-time PCR. The relative expression level of IFN-γ, IL-2, and TNF-α were higher in <italic>EmagER</italic>-immunized rabbits than wild-type parasites-immunized rabbits after stimulation with EYFP and RFP. Our study confirmed that a specific immune response was induced by the exogenous protein expressed by <italic>EmagER</italic> and favored future studies on application of transgenic rabbit coccidia as recombinant vaccine vectors.</p>