title: The immune response induced by DNA vaccine expressing nfa1 gene against Naegleria fowleri.
abstract: The pathogenic free-living amoeba, Naegleria fowleri, causes fatal primary amoebic meningoencephalitis in experimental animals and in humans. The nfa1 gene that was cloned from N. fowleri is located on pseudopodia, especially amoebic food cups and plays an important role in the pathogenesis of N. fowleri. In this study, we constructed and characterized retroviral vector and lentiviral vector systems for nfa1 DNA vaccination in mice. We constructed the retroviral vector (pQCXIN) and the lentiviral vector (pCDH) cloned with the egfp-nfa1 gene. The expression of nfa1 gene in Chinese hamster ovary cell and human primary nasal epithelial cell transfected with the pQCXIN/egfp-nfa1 vector or pCDH/egfp-nfa1 vector was observed by fluorescent microscopy and Western blotting analysis. Our viral vector systems effectively delivered the nfa1 gene to the target cells and expressed the Nfa1 protein within the target cells. To evaluate immune responses of nfa1-vaccinated mice, BALB/c mice were intranasally vaccinated with viral particles of each retro- or lentiviral vector expressing nfa1 gene. DNA vaccination using viral vectors expressing nfa1 significantly stimulated the production of Nfa1-specific IgG subclass, as well as IgG levels. In particular, both levels of IgG2a (Th1) and IgG1 (Th2) were significantly increased in mice vaccinated with viral vectors. These results show the nfa1-vaccination induce efficiently Th1 type, as well as Th2 type immune responses. This is the first report to construct viral vector systems and to evaluate immune responses as DNA vaccination in N. fowleri infection. Furthermore, these results suggest that nfal vaccination may be an effective method for treatment of N. fowleri infection.
authors.affiliation: Department of Microbiology, Ajou University School of Medicine, Suwon 443-721, Republic of Korea.
authors.forename: Jong-Hyun
authors.initials: JH
authors.lastname: Kim
authors.forename: Sang-Hee
authors.initials: SH
authors.lastname: Lee
authors.forename: Hae-Jin
authors.initials: HJ
authors.lastname: Sohn
authors.forename: Jinyoung
authors.initials: J
authors.lastname: Lee
authors.forename: Yong-Joon
authors.initials: YJ
authors.lastname: Chwae
authors.forename: Sun
authors.initials: S
authors.lastname: Park
authors.forename: Kyongmin
authors.initials: K
authors.lastname: Kim
authors.forename: Ho-Joon
authors.initials: HJ
authors.lastname: Shin
mesh_terms: D000562:Amebiasis / Q000517:prevention & control*; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D000953:Antigens, Protozoan / Q000235:genetics / Q000276:immunology*; D002460:Cell Line; D020808:Central Nervous System Protozoal Infections / Q000517:prevention & control*; D006224:Cricetinae; D004195:Disease Models, Animal; D015870:Gene Expression; D005822:Genetic Vectors; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D016086:Lentivirus / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D016848:Naegleria fowleri / Q000235:genetics / Q000276:immunology*; D015800:Protozoan Proteins / Q000235:genetics / Q000276:immunology*; D016052:Protozoan Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D007074:Immunoglobulin G; C460560:Nfa1 protein, Naegleria fowleri; D015800:Protozoan Proteins; D016052:Protozoan Vaccines; D019444:Vaccines, DNA; D014614:Vaccines, Synthetic