title: Twenty-six circulating antigens and two novel diagnostic candidate molecules identified in the serum of canines with experimental acute toxoplasmosis.
abstract: The protozoan Toxoplasma gondii is a pathogen that causes severe opportunistic disease in a wide range of hosts. Efficient methods to diagnose acute T. gondii infection are essential for the administration of appropriate treatments and to reduce economic losses. In animals with acute infections, circulating antigens (CAgs) were detected as early as two days post-infection; these CAgs were reliable diagnostic indicators of acute infection. However, only a limited number of CAgs have been identified to date. The objective of this study was to identify a broader spectrum of CAgs and to explore novel diagnostic candidates in serum.
  
  
  
  A canine model of acute toxoplasmiosis was established. For this purpose, six dogs were infected by intraperitoneal inoculation of tachyzoites. The CAgs spectrum in the serum was identified with the immunoprecipitation-shotgun approach. Two CAgs with low homology to other species, coronin protein (TgCOR) and ELMO protein (TgELMO), were heterologously expressed in Escherichia coli. Polyclonal antibodies against these two proteins were prepared, and the presence of these proteins in the serum was verified by Western blotting. The two CAgs were detected and evaluated by indirect ELISA methods.
  
  
  
  The CAgs levels peaked between two and five days after inoculation, and twenty-six CAgs were identified. Western blotting showed the presence of the two proteins in the serum during acute infection. Based on ELISA tests, the two CAgs were detected during acute infection.
  
  
  
  We identified twenty-six CAgs in the serum of canines with experimental acute toxoplasmosis and discovered two novel diagnostic candidates. We also provide new insights into the diagnosis of acute toxoplasmosis.
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China.|Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, 200241, China.
authors.forename: Junxin
authors.initials: J
authors.lastname: Xue
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, 200241, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Jiang
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, 200241, China.
authors.forename: Yongjun
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, 200241, China.
authors.forename: Yingchun
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, 200241, China.
authors.forename: Huajing
authors.initials: H
authors.lastname: Zhang
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: College of Food Sciences, Shanghai University, Shanghai, 200444, China.
authors.forename: Yuanbiao
authors.initials: Y
authors.lastname: Qiao
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China. khhuang@njau.edu.cn.
authors.forename: Kehe
authors.initials: K
authors.lastname: Huang
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, 200241, China. wangquan@shvri.ac.cn.
authors.forename: Quan
authors.initials: Q
authors.lastname: Wang
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan / Q000097:blood*; D004283:Dog Diseases / Q000469:parasitology*; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D014122:Toxoplasma / Q000276:immunology*; D014124:Toxoplasmosis, Animal / Q000097:blood*
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan
keywords: Acute infection; Circulating antigens; Diagnostic candidates; Proteomics; Toxoplasma gondii