title: Transgenic Eimeria tenella as a vaccine vehicle: expressing TgSAG1 elicits protective immunity against Toxoplasma gondii infections in chickens and mice.
abstract: The surface antigen 1 of Toxoplasma gondii (TgSAG1) is a major immunodominant antigen and is widely considered an ideal candidate for the development of an effective recombinant vaccine against toxoplasmosis. Eimeria tenella, an affinis apicomplexan parasite with T. gondii, is a potential vaccine vector carrying exogenous antigens that stimulates specific immune responses. Here, we engineered TgSAG1 into E. tenella and obtained a stably transfected E. tenella line (Et-TgSAG1). We found TgSAG1 localized on the cell surface of Et-TgSAG1, which is similar to its native distribution in T. gondii tachyzoites. We immunized the chickens with Et-TgSAG1 orally and detected TgSAG1-specific immune responses, which partly reduced T. gondii infection. In the mouse model, we immunized the mice with Et-TgSAG1 sporozoites intraperitoneally and challenged them with T. gondii tachyzoites RH strain. We found that the mice immunized with Et-TgSAG1 showed a TgSAG1 specific Th 1-dominant immune response and a prolonged survival time compared with wild-type E. tenella and non-immunized mice. Collectively, our results demonstrated that Et-TgSAG1, utilized as a recombinant vaccine against toxoplasmosis, could be applied in both chickens and mice. Our findings also provide a promising persuasion for the development of transgenic Eimeria as vaccine vectors for use in birds and mammals.
authors.affiliation: State Key Laboratory of Agrobiotechnology &Key Laboratory of Zoonosis of Ministry of Agriculture &National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
authors.forename: Xinming
authors.initials: X
authors.lastname: Tang
authors.affiliation: Engineering Laboratory of Animal Pharmaceuticals, College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian Province, China.
authors.forename: Guangwen
authors.initials: G
authors.lastname: Yin
authors.affiliation: State Key Laboratory of Agrobiotechnology &Key Laboratory of Zoonosis of Ministry of Agriculture &National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Qin
authors.affiliation: State Key Laboratory of Agrobiotechnology &Key Laboratory of Zoonosis of Ministry of Agriculture &National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
authors.forename: Geru
authors.initials: G
authors.lastname: Tao
authors.affiliation: State Key Laboratory of Agrobiotechnology &Key Laboratory of Zoonosis of Ministry of Agriculture &National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
authors.forename: Jingxia
authors.initials: J
authors.lastname: Suo
authors.affiliation: State Key Laboratory of Agrobiotechnology &Key Laboratory of Zoonosis of Ministry of Agriculture &National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
authors.forename: Xianyong
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Agrobiotechnology &Key Laboratory of Zoonosis of Ministry of Agriculture &National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
authors.forename: Xun
authors.initials: X
authors.lastname: Suo
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000378:metabolism; D000953:Antigens, Protozoan / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D002645:Chickens / Q000276:immunology; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D004195:Disease Models, Animal; D016786:Eimeria tenella / Q000235:genetics* / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D015800:Protozoan Proteins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D016052:Protozoan Vaccines / Q000008:administration & dosage* / Q000276:immunology; D014122:Toxoplasma / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D014123:Toxoplasmosis / Q000276:immunology / Q000517:prevention & control*; D014611:Vaccination; D014709:Vero Cells
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D015800:Protozoan Proteins; D016052:Protozoan Vaccines; C047168:SAG1 antigen, Toxoplasma