title: Design of different strategies of multivalent DNA-based vaccination against rabies and canine distemper in mice and dogs.
abstract: BACKGROUND
  During the vaccination campaigns, puppies younger than 3 months old are not targeted and remain unvaccinated for at least the first year of their lives. Almost half of the reported rabid dogs are 6 months or younger. Hence, we should recommend the vaccination against rabies of young puppies. Unfortunately, owing to the exposure of puppies to infections with either canine parvovirus (CPV) or distemper virus (CDV) after the intervention of the vaccinators, owners are reluctant to vaccinate puppies against rabies. Therefore, it is necessary to include the CPV and CDV valences in the vaccine against rabies. Multivalent DNA-based vaccination in dogs, including rabies and distemper valences, could help in raising vaccine coverage.
  
  
  METHODS
  We have designed monovalent and multivalent DNA-based vaccine candidates for in vitro and in vivo assays. These plasmids encode to the rabies virus glycoprotein and/or the canine distemper virus hemagglutinin. The first strategy of multivalent DNA-based vaccination is by mixing plasmids encoding to a single antigen each. The second is by simply fusing the genes of the antigens together. The third is by adding the foot and mouth disease virus (FMDV) 2A oligopeptide gene into the antigen genes. The last strategy is by the design and use of a bicistronic plasmid with an "Internal Ribosome Entry Site" (IRES) domain.
  
  
  RESULTS
  The monovalent construct against canine distemper was efficiently validated by inducing higher humoral immune responses compared to cell-culture-derived vaccine both in mice and dogs. All multivalent plasmids efficiently expressed both valences after in vitro transfection of BHK-21 cells. In BALB/c mice, the bicistronic IRES-dependant construct was the most efficient inducer of virus-neutralizing antibodies against both valences. It was able to induce better humoral immune responses compared to the administration of either cell-culture-derived vaccines or monovalent plasmids. The FMDV 2A was also efficient in the design of multivalent plasmids.
  
  
  CONCLUSIONS
  In a single shot, the design of efficient multivalent plasmids will be very beneficial for DNA-based vaccination against numerous diseases.
authors.affiliation: Institut Pasteur de Tunis, MMVDB, 13, Place Pasteur BP-74, Tunis-Belvedere, 1002, Tunisia.
authors.forename: Leila
authors.initials: L
authors.lastname: Touihri
authors.forename: Sami Belhaj
authors.initials: SB
authors.lastname: Ahmed
authors.forename: Yacine
authors.initials: Y
authors.lastname: Chtourou
authors.forename: Rahma
authors.initials: R
authors.lastname: Daoud
authors.forename: Chokri
authors.initials: C
authors.lastname: Bahloul
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000276:immunology; D000914:Antibodies, Viral / Q000276:immunology; D000956:Antigens, Viral / Q000276:immunology; D002522:Chlorocebus aethiops; D004216:Distemper / Q000235:genetics / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D004217:Distemper Virus, Canine / Q000276:immunology*; D004285:Dogs / Q000276:immunology / Q000821:virology; D005260:Female; D029544:Foot-and-Mouth Disease Virus / Q000235:genetics / Q000378:metabolism; D050939:Gene Fusion; D005814:Genes, Viral; D006389:Hemagglutinins, Viral / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D056724:Immunity, Humoral; D051379:Mice; D008807:Mice, Inbred BALB C; D010957:Plasmids / Q000378:metabolism; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism; D011818:Rabies / Q000276:immunology / Q000517:prevention & control* / Q000662:veterinary*; D011819:Rabies Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D011820:Rabies virus / Q000276:immunology; D014162:Transfection; D014611:Vaccination / Q000379:methods*; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000276:immunology; D014709:Vero Cells; D014764:Viral Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D000956:Antigens, Viral; D006389:Hemagglutinins, Viral; D012367:RNA, Viral; D011819:Rabies Vaccines; D019444:Vaccines, DNA; D014764:Viral Proteins