title: Partial protective effect of intranasal immunization with recombinant Toxoplasma gondii rhoptry protein 17 against toxoplasmosis in mice.
abstract: Toxoplasma gondii (T. gondii) is an obligate intracellular protozoan parasite that infects a variety of mammals, including humans. An effective vaccine for this parasite is therefore needed. In this study, RH strain T. gondii rhoptry protein 17 was expressed in bacteria as a fusion with glutathione S-transferase (GST) and the recombinant proteins (rTgROP17) were purified via GST-affinity chromatography. BALB/c mice were nasally immunised with rTgROP17, and induction of immune responses and protection against chronic and lethal T. gondii infections were investigated. The results revealed that mice immunised with rTgROP17 produced high levels of specific anti-rTgROP17 IgGs and a mixed IgG1/IgG2a response of IgG2a predominance. The systemic immune response was associated with increased production of Th1 (IFN-γand IL-2) and Th2 (IL-4) cytokines, and enhanced lymphoproliferation (stimulation index, SI) in the mice immunised with rTgROP17. Strong mucosal immune responses with increased secretion of TgROP17-specific secretory IgA (SIgA) in nasal, vaginal and intestinal washes were also observed in these mice. The vaccinated mice displayed apparent protection against chronic RH strain infection as evidenced by their lower liver and brain parasite burdens (59.17% and 49.08%, respectively) than those of the controls. The vaccinated mice also exhibited significant protection against lethal infection of the virulent RH strain (survival increased by 50%) compared to the controls. Our data demonstrate that rTgROP17 can trigger strong systemic and mucosal immune responses against T. gondii and that ROP17 is a promising candidate vaccine for toxoplasmosis.
authors.affiliation: Research Institute of Medical Parasitology, Shanxi Medical University, Taiyuan, Shanxi, PR China.
authors.forename: Hai-Long
authors.initials: HL
authors.lastname: Wang
authors.affiliation: Research Institute of Medical Parasitology, Shanxi Medical University, Taiyuan, Shanxi, PR China.
authors.forename: Tie-E
authors.initials: TE
authors.lastname: Zhang
authors.affiliation: Department of Physiology, Key Laboratory of Cellular Physiology Co-constructed by Province and Ministry of Education, Shanxi Medical University, Taiyuan, Shanxi, PR China.
authors.forename: Li-Tian
authors.initials: LT
authors.lastname: Yin
authors.affiliation: Department of Respiratory, the First Affiliated Hospital, Shanxi Medical University, Taiyuan, Shanxi, PR China.
authors.forename: Min
authors.initials: M
authors.lastname: Pang
authors.affiliation: Research Institute of Medical Parasitology, Shanxi Medical University, Taiyuan, Shanxi, PR China.
authors.forename: Li
authors.initials: L
authors.lastname: Guan
authors.affiliation: Research Institute of Medical Parasitology, Shanxi Medical University, Taiyuan, Shanxi, PR China.
authors.forename: Hong-Li
authors.initials: HL
authors.lastname: Liu
authors.affiliation: Research Institute of Medical Parasitology, Shanxi Medical University, Taiyuan, Shanxi, PR China.
authors.forename: Jian-Hong
authors.initials: JH
authors.lastname: Zhang
authors.affiliation: Research Institute of Medical Parasitology, Shanxi Medical University, Taiyuan, Shanxi, PR China.
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Meng
authors.affiliation: Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.
authors.forename: Ji-Zhong
authors.initials: JZ
authors.lastname: Bai
authors.affiliation: Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan, Shanxi, PR China.
authors.forename: Guo-Ping
authors.initials: GP
authors.lastname: Zheng
authors.affiliation: Research Institute of Medical Parasitology, Shanxi Medical University, Taiyuan, Shanxi, PR China.
authors.forename: Guo-Rong
authors.initials: GR
authors.lastname: Yin
mesh_terms: D000281:Administration, Intranasal; D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology; D000953:Antigens, Protozoan / Q000008:administration & dosage / Q000276:immunology*; D016207:Cytokines / Q000378:metabolism; D005260:Female; D007114:Immunization; D007070:Immunoglobulin A / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology / Q000378:metabolism; D051379:Mice; D015800:Protozoan Proteins / Q000008:administration & dosage / Q000276:immunology*; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000276:immunology*; D014122:Toxoplasma / Q000276:immunology*; D014124:Toxoplasmosis, Animal / Q000469:parasitology / Q000517:prevention & control*
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D016207:Cytokines; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D015800:Protozoan Proteins; D011994:Recombinant Proteins