title: Construction of recombinant Mip-FlaA dominant epitope vaccine against Legionella pneumophila and evaluation of the immunogenicity and protective immunity.
abstract: Legionnaires' disease, a kind of systemic disease with pneumonia as the main manifestation, is caused by Legionella pneumophila (L. pneumophila). In order to prevent the disease, we optimized Mip and FlaA, the virulence factors of L. pneumophila, to design recombinant Mip-FlaA dominant epitope vaccine against the pathogen. Firstly, the coding sequences of mip and flaA were optimized by DNAStar software and Expasy protein analysis system, and then, the tertiary structure and function of recombinant Mip-FlaA were predicted by PHYRE2 Protein Fold Recognition Server. After that, the optimized mip, flaA and mip-flaA were cloned, expressed and purified, and the proteins were used as dominant epitope vaccines to immunize BABL/c mice. Moreover, the IgG titers, histological changes in lung and the level of TNF-α, IFN-γ, IL-6 and IL-1β were detected to reflect the immunogenicity and protective immunity of the vaccines. The results of SDS-PAGE and Western blot proved the recombinant Mip-FlaA was successfully expressed. ELISA results of IgG titers and these cytokines showed Mip-FlaA group was capable to induce the strongest immune response, compared to PBS, Mip and FlaA groups. In addition, histopathology analysis demonstrated the mice immunized with Mip-FlaA showed better immune protection. Therefore, the work indicated that the above-described biological tools were useful in optimization of epitope vaccine. Antigenic characterization and immune protection of recombinant Mip-FlaA would be of great value in understanding the immunopathogenesis of the disease and in developing possible vaccine against the pathogen.
authors.affiliation: Department of Parasitology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, 610041, China.
authors.forename: Jinlei
authors.initials: J
authors.lastname: He
authors.affiliation: Department of Parasitology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, 610041, China.
authors.forename: Junrong
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Parasitology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, 610041, China.|Department of Pathogen Biology and Immunology, Medical College, Hubei University for Nationalities, Enshi, 445000, China.
authors.forename: Yanxia
authors.initials: Y
authors.lastname: He
authors.affiliation: First Department of Hepatobiliary Surgery, Qinghai University Affiliated Hospital, Medical College of Qinghai University, Xining, 810016, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Huang
authors.affiliation: Department of Parasitology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, 610041, China.
authors.forename: Jiao
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Parasitology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, 610041, China.
authors.forename: Qiwei
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Department of Parasitology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, 610041, China.
authors.forename: Dali
authors.initials: D
authors.lastname: Chen
authors.affiliation: Department of Parasitology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, 610041, China. jianpc007@163.com.|Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province, School of Life Science, Sichuan University, Chengdu, 610041, China. jianpc007@163.com.
authors.forename: Jianping
authors.initials: J
authors.lastname: Chen
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001428:Bacterial Vaccines / Q000235:genetics / Q000276:immunology*; D005260:Female; D005408:Flagellin / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007113:Immunity, Innate; D016056:Immunodominant Epitopes / Q000235:genetics; D016952:Legionella pneumophila / Q000276:immunology* / Q000472:pathogenicity; D007877:Legionnaires' Disease / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D019696:Peptidylprolyl Isomerase / Q000235:genetics / Q000378:metabolism; D015202:Protein Engineering; D022223:Vaccines, Subunit / Q000235:genetics / Q000276:immunology; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D001428:Bacterial Vaccines; D016056:Immunodominant Epitopes; D022223:Vaccines, Subunit; D005408:Flagellin; C067138:flaA protein, bacteria; C512922:Mip protein, Legionella pneumophila; D019696:Peptidylprolyl Isomerase
keywords: Epitope vaccine; FlaA; Immunity; Legionella pneumophila; Mip