title: Subunit Vaccine Preparation of Bovine Rotavirus and Its Efficacy in Mice.
abstract: BACKGROUND
  Rotaviruses (RV) are important viral diarrheal agents in calves. Vaccination is an optimum measure to prevent bovine rotaviruses (BRV) infection. However, little research on BRV VP7 vaccine has been done and currently there is no BRV vaccine.
  
  
  OBJECTIVE
  To prepare a subunit vaccine of BRV and investigate its efficacy.
  
  
  METHODS
  Total RNA was extracted from MA104 cells infected with bovine rotavirus (BRV) strain GSB01. BRV VP7 gene was amplified using real time fluorescence quantitative PCR (qPCR). The pEASY-T3-VP7 plasmid was digested using HindⅢ and BamHI restriction endonucleases, then recombined into the prokaryotic expression vector pET32a. The pET32a-VP7 and pET32a-VP7-LTB (heat-labile enterotoxin B subunit) were transformed into BL21 (DE3) competent cells of Escherichia coli, respectively, and induced with IPTG, then analyzed using SDS-PAGE. Sixty mice were randomly divided into three groups (n=20). Group A mice was used as His-tag control and mice in group B and C were inoculated with pET32a-VP7 and pET32a-VP7-LTB, respectively. VP7 IgG antibody titers and protection efficiency of pET32a-VP7-LTB were further determined in neonatal mice challenged with GSB01 BRV strain.
  
  
  RESULTS
  SDS-PAGE analysis showed that the pET32a-VP7 was highly expressed in the BL21 (DE3) cells. PET32a-VP7 and pET32a-VP7-LTB protein could promote VP7 IgG antibody titer（8.33×103 vs. 17.26×103）in mice. Immunization protection ratios of pET32a-VP7 and pET32a-VP7-LTB proteins in the neonatal mice were 86.4% and 91.7%, respectively.
  
  
  CONCLUSIONS
  The fusion protein of pET32a-VP7-LTB had excellent immunogenicity and protected mice from BRV infection. Our findings can be used for further developing of a high-efficiency subunit vaccine of BRV.
authors.affiliation: Life Science and Engineering College, Northwest University for Nationalities, Lanzhou, China, email: weisc668@163.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Suocheng
authors.forename: Che
authors.initials: C
authors.lastname: Tuanjie
authors.forename: Song
authors.initials: S
authors.lastname: Changjun
authors.forename: Tian
authors.initials: T
authors.lastname: Fengling
authors.forename: Ma
authors.initials: M
authors.lastname: Zhongren
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000914:Antibodies, Viral; D000956:Antigens, Viral / Q000235:genetics / Q000378:metabolism*; D036022:Capsid Proteins / Q000235:genetics / Q000378:metabolism*; D002417:Cattle; D004768:Enterotoxins / Q000235:genetics / Q000378:metabolism*; D053308:Lymphotoxin-beta / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D015202:Protein Engineering; D011993:Recombinant Fusion Proteins / Q000008:administration & dosage*; D012401:Rotavirus / Q000276:immunology*; D012400:Rotavirus Infections / Q000276:immunology / Q000517:prevention & control*; D022223:Vaccines, Subunit; D014765:Viral Vaccines
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D036022:Capsid Proteins; D004768:Enterotoxins; D053308:Lymphotoxin-beta; D011993:Recombinant Fusion Proteins; C050779:VP7 protein, Rotavirus; D022223:Vaccines, Subunit; D014765:Viral Vaccines