title: Recombinant Leishmania tarentolae encoding the HPV type 16 E7 gene in tumor mice model.
abstract: BACKGROUND
  Cervical cancer, the third most prevalent cause of cancer in women worldwide, is associated with HPVs. The critical role of E7 protein in HPV-related malignancies has designated it as a strong contender for generating vaccines against HPV.
  
  
  METHODS
  In this study, we developed a novel live vaccine using recombinant Leishmania tarentolae expressing E7-green fluorescent protein (GFP) fusion protein for the protection of mice against HPV-associated tumors. In order to transfect L. tarentolae with E7-GFP fusion construct, pLEXSY-neo2 system was applied. Followed by PCR, fluorescence imaging and fluorescence-activated cell sorting analysis, integration of E7-GFP gene into parasites genome was confirmed. A comparative study of six groups of C57BL/6 mice was performed to analyze antigen-specific humoral and cellular immune responses against E7 encoding live and DNA vaccines. Furthermore, the anti-tumor protective effect of L. tarentolae-E7-GFP was compared to other vaccination strategies, namely pcDNA-E7 as the DNA vaccine and pcDNA-E7/L. tarentolae-E7-GFP as the prime-boost regimen.
  
  
  RESULTS
  We found that E7-GFP expressing recombinant L. tarentolae induces significant levels of IgG2a and IFN-γ, while there is no significant IL-5 production compared with that of other strategies and control groups before and after challenge with TC-1 tumor cells. It is noteworthy that the designed live vaccine showed the best protection and minimum tumor size among all groups against TC-1-induced tumors.
  
  
  CONCLUSIONS
  Overall, the results obtained revealed that the E7-GFP recombinant L. tarentolae could be a potential live vaccine for induction of immune responses in vivo.
authors.affiliation: Molecular Immunology & Vaccine Research Laboratory, Pasteur Institute of Iran, Tehran, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Salehi
authors.forename: Tahereh
authors.initials: T
authors.lastname: Taheri
authors.forename: Elham
authors.initials: E
authors.lastname: Mohit
authors.forename: Farnaz
authors.initials: F
authors.lastname: Zahedifard
authors.forename: Negar
authors.initials: N
authors.lastname: Seyed
authors.forename: Yasaman
authors.initials: Y
authors.lastname: Taslimi
authors.forename: Mandana
authors.initials: M
authors.lastname: Sattari
authors.forename: Azam
authors.initials: A
authors.lastname: Bolhassani
authors.forename: Sima
authors.initials: S
authors.lastname: Rafati
mesh_terms: D000818:Animals; D002461:Cell Line, Transformed; D004195:Disease Models, Animal; D005260:Female; D005822:Genetic Vectors; D052162:Human papillomavirus 16 / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism; D007371:Interferon-gamma / Q000378:metabolism; D015848:Interleukin-5 / Q000378:metabolism; D007891:Leishmania; D051379:Mice; D008810:Mice, Inbred C57BL; D050725:Papillomavirus E7 Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D030361:Papillomavirus Infections / Q000517:prevention & control*; D053918:Papillomavirus Vaccines / Q000235:genetics / Q000276:immunology*; D019076:Transgenes / Q000235:genetics; D047368:Tumor Burden; D002583:Uterine Cervical Neoplasms / Q000517:prevention & control*
chemical_list: D007074:Immunoglobulin G; D015848:Interleukin-5; D050725:Papillomavirus E7 Proteins; D053918:Papillomavirus Vaccines; C059731:oncogene protein E7, Human papillomavirus type 16; D007371:Interferon-gamma