title: Immunogenicity and efficacy of a bivalent DNA vaccine containing LeIF and TSA genes against murine cutaneous leishmaniasis.
abstract: There is no effective vaccine for the prevention and elimination of leishmaniasis. For this reason, we assessed the protective effects of DNA vaccines containing LeIF, TSA genes alone, or LeIF-TSA fusion against cutaneous leishmaniasis pEGFP-N1 plasmid (empty vector) and phosphate buffer saline (PBS) were used as control groups. Therefore, cellular and humoral immune responses were evaluated before and after the challenge with Leishmania major. Lesion diameter was also measured 3-12 weeks after challenge. All immunized mice with plasmid DNA encoding Leishmania antigens induced the partial immunity characterized by increased IFN-γ and IgG2a levels compared with control groups (p < 0.001). Furthermore, the immunized mice showed significant reduction in mean lesion sizes compared with mice in empty vector and PBS groups (p < 0.05). The reduction in lesion diameter was 29.3%, 34.1%, and 46.2% less in groups vaccinated with LeIF, TSA, and LeIF-TSA, respectively, than in PBS group at 12th week post infection. IFN/IL-4 and IgG2a/IgG1 ratios indicated that group receiving LeIF-TSA fusion had the highest IFN-γ and IgG2a levels. In this study, DNA immunization promoted Th1 immune response characterized by higher IFN-γ and IgG2a levels and also reduction in lesion size. These results showed that a bivalent vaccine containing two distinct antigens may induce more potent immune responses against leishmaniasis.
authors.affiliation: Department of Medical Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
authors.forename: Nahid
authors.initials: N
authors.lastname: Maspi
authors.affiliation: Department of Medical Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Ghaffarifar
authors.affiliation: Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran.
authors.forename: Zohreh
authors.initials: Z
authors.lastname: Sharifi
authors.affiliation: Department of Medical Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
authors.forename: Abdolhossein
authors.initials: A
authors.lastname: Dalimi
authors.affiliation: Department of Medical Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
authors.forename: Mohammad Saaid
authors.initials: MS
authors.lastname: Dayer
mesh_terms: D000818:Animals; D015153:Blotting, Western; D004195:Disease Models, Animal; D005260:Female; D016773:Leishmaniasis, Cutaneous; D051379:Mice; D008807:Mice, Inbred BALB C; D010448:Peptide Initiation Factors / Q000235:genetics* / Q000276:immunology; D054464:Peroxiredoxins / Q000235:genetics / Q000276:immunology*; D016133:Polymerase Chain Reaction; D015800:Protozoan Proteins / Q000235:genetics* / Q000276:immunology; D019444:Vaccines, DNA / Q000235:genetics / Q000276:immunology*
chemical_list: C092810:LeIF protein, Leishmania; D010448:Peptide Initiation Factors; D015800:Protozoan Proteins; D019444:Vaccines, DNA; D054464:Peroxiredoxins
keywords: 
  Leishmania major
  ; Leishmania eukaryotic initiation factor; fusion; thiol-specific antioxidant; vaccine