title: Molecular characterization and protective efficacy of silent information regulator 2A from Eimeria tenella.
abstract: Silent information regulator 2 (SIR2) proteins are a family of NAD + -dependent protein deacetylases that are considered potential targets for anti-parasitic agents. In this study, we cloned and characterized SIR2A of the protozoan parasite Eimeria tenella (EtSIR2A) and investigated its protective efficacy as a DNA vaccine.
  
  
  
  The EtSIR2A gene encoding 33.37 kDa protein from E. tenella second-generation merozoites was cloned, and recombinant EtSIR2A protein (rEtSIR2A) was produced in an Escherichia coli expression system. The rEtSIR2A was used to immunize rabbits. Anti-rEtSIR2A antibodies were used to determine the immunolocolization of EtSIR2A in the parasite by immunofluorescence assay (IFA). Transcript and protein expression of EtSIR2A in different development stages of E. tenella were observed by quantitative real-time PCR (qPCR) and western blot (WB) analysis, respectively. The recombinant plasmid pCAGGS-EtSIR2A was constructed and its efficacy against E. tenella infection in chickens was evaluated.
  
  
  
  qPCR and WB analysis revealed EtSIR2A expression was developmentally regulated at both the mRNA and protein levels. EtSIR2A mRNA levels were higher in unsporulated oocysts than at other developmental stages, including sporulated oocysts, sporozoites and second-generation merozoites. In contrast, EtSIR2A protein expression levels were highest in second-generation merozoites, moderate in unsporulated oocysts and sporulated oocysts and lowest in sporozoites. Immunostaining with anti-rEtSIR2A antibody indicated that EtSIR2A was mainly located in the cytoplasm of sporozoites and second-generation merozoites, and was strongly expressed during first stage schizogony. Animal-challenge experiments demonstrated that immunization with pCAGGS-EtSIR2A significantly increased average body-weight gain, and decreased mean lesion score and oocyst output in chickens.
  
  
  
  These results suggest that EtSIR2A may play an important role in parasite cell survival and may be an effective candidate for the development of new vaccines against E. tenella infection in chickens.
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai, 200241, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Dong
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai, 200241, China.|College of Animal Science and Technology, Yunnan Agricultural University, Kunming, 650201, China.
authors.forename: Sihan
authors.initials: S
authors.lastname: Yang
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai, 200241, China.
authors.forename: Qiping
authors.initials: Q
authors.lastname: Zhao
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai, 200241, China.
authors.forename: Hongyu
authors.initials: H
authors.lastname: Han
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai, 200241, China.
authors.forename: Shunhai
authors.initials: S
authors.lastname: Zhu
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai, 200241, China.
authors.forename: Xuelong
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai, 200241, China.
authors.forename: Cong
authors.initials: C
authors.lastname: Li
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai, 200241, China.
authors.forename: Ziwen
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai, 200241, China.
authors.forename: Weili
authors.initials: W
authors.lastname: Xia
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai, 200241, China.
authors.forename: Qifei
authors.initials: Q
authors.lastname: Men
authors.affiliation: College of Animal Science and Technology, Yunnan Agricultural University, Kunming, 650201, China.
authors.forename: Liangyu
authors.initials: L
authors.lastname: Yang
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai, 200241, China. hb@shvri.ac.com.|Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China. hb@shvri.ac.com.
authors.forename: Bing
authors.initials: B
authors.lastname: Huang
mesh_terms: D000818:Animals; D002460:Cell Line; D002645:Chickens; D003001:Cloning, Molecular; D003048:Coccidiosis / Q000517:prevention & control / Q000662:veterinary*; D004274:DNA, Recombinant / Q000276:immunology; D016786:Eimeria tenella / Q000201:enzymology / Q000235:genetics* / Q000276:immunology; D011201:Poultry Diseases / Q000469:parasitology* / Q000517:prevention & control; D015800:Protozoan Proteins / Q000235:genetics*; D056565:Sirtuin 2 / Q000235:genetics*; D019444:Vaccines, DNA / Q000235:genetics / Q000276:immunology*
chemical_list: D004274:DNA, Recombinant; D015800:Protozoan Proteins; D019444:Vaccines, DNA; D056565:Sirtuin 2
keywords: Coccidia; Eimeria; Recombinant plasmid; Silent information regulator 2