title: Comparative efficacy of a multi-epitope DNA vaccine via intranasal, peroral, and intramuscular delivery against lethal Toxoplasma gondii infection in mice.
abstract: BACKGROUND
  Toxoplasmosis is an important zoonosis, being a cause of congenital disease and abortion in animals and humans. DNA vaccination as a promising vaccine remains a challenge for an improved delivery system.
  
  
  METHODS
  In this study, attenuated Salmonella typhimurium BRD509 was used to deliver a DNA vaccine encoding several epitopes, derived from the tachyzoite proteins SAG1, GRA1, ROP2, GRA4 and bradyzoite proteins SAG2C, SAG2X of Toxoplasma gondii and A2/B subunit of cholera toxin. The recombinant plasmids were electroporated into attenuated Salmonella typhimurium. Humoral and cellular immune responses were evaluated for BALB/c mice administered with this attenuated recombinant Salmonella vaccine via the oral and nasal route or by intramuscular injection with DNA plasmid directly.
  
  
  RESULTS
  High IgG levels were present in the mice immunized intramuscularly, while IgA levels were higher in the oral and nasal immunization groups. Furthermore, cellular immunity was activated in oral immunization groups with 60% survival rate following challenge with high virulent RH strain.
  
  
  CONCLUSIONS
  The results from this study indicate that a DNA vaccine encoding multi-epitopes of T. gondii delivered by attenuated Salmonella is promising.
authors.affiliation: Department of human parasitology, Medical school, Shandong University, No,44 Wenhuaxi Road, Jinan, Shandong 250012, P, R, China. conghua@sdu.edu.cn.
authors.forename: Hua
authors.initials: H
authors.lastname: Cong
authors.forename: Quan
authors.initials: Q
authors.lastname: Yuan
authors.forename: Qunli
authors.initials: Q
authors.lastname: Zhao
authors.forename: Lingxiao
authors.initials: L
authors.lastname: Zhao
authors.forename: Huiquan
authors.initials: H
authors.lastname: Yin
authors.forename: Huaiyu
authors.initials: H
authors.lastname: Zhou
authors.forename: Shenyi
authors.initials: S
authors.lastname: He
authors.forename: Zhiyu
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000281:Administration, Intranasal; D000284:Administration, Oral; D000818:Animals; D000939:Epitopes; D007273:Injections, Intramuscular; D051379:Mice; D016052:Protozoan Vaccines / Q000008:administration & dosage / Q000276:immunology*; D012486:Salmonella typhimurium / Q000378:metabolism; D014122:Toxoplasma; D014124:Toxoplasmosis, Animal / Q000517:prevention & control*; D019444:Vaccines, DNA / Q000276:immunology
chemical_list: D000939:Epitopes; D016052:Protozoan Vaccines; D019444:Vaccines, DNA