Recombinant Mip-PilE-FlaA dominant epitopes vaccine candidate against Legionella pneumophila

Immunol Lett. 2017 Jun;186:33-40. doi: 10.1016/j.imlet.2017.03.016. Epub 2017 Mar 31.


Legionella pneumophila is the main causative agent of Legionnaires' disease, which is a severe multi-system disease with pneumonia as the primary manifestation. We designed a recombinant Mip-PilE-FlaA dominant epitopes vaccine against Legionella pneumophila to prevent the disease and evaluated its immunogenicity and protective immunity. The protein structures of Mip, PilE and FlaA were analyzed using a computer, and the gene sequences of the dominant epitopes of the three proteins were selected to construct and optimize the vaccine. The optimized mip, pilE, flaA and recombinant mip-pilE-flaA gene sequences were cloned, expressed and purified. The purified proteins were used as dominant epitopes vaccines to immunize BALB/c mice and determine the protective immunity and immunogenicity of these purified proteins. The identification confirmed that the recombinant mip-pilE-flaA was successfully cloned and expressed. ELISA revealed that the Mip-PilE-FlaA group produced the highest IgG response, and this protein may considerably improve the production of some cytokines in BALB/c mice. Histopathology analyses of lungs from mice immunized with Mip-PilE-FlaA revealed a certain protective effect. Our work demonstrated that the recombinant dominant epitopes of Mip-PilE-FlaA exhibited strong immunogenicity and immune protection, and this protein may be an efficient epitopes vaccine candidate against Legionella pneumophila.

Keywords: Epitopes vaccine; FlaA; Immunity; Legionella pneumophila; Mip; PilE.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Bacterial / genetics
  • Bacterial Proteins / genetics
  • Bacterial Vaccines / genetics
  • Bacterial Vaccines / immunology*
  • Computer Simulation
  • Female
  • Flagellin / genetics
  • Humans
  • Immunity, Humoral
  • Immunization
  • Immunodominant Epitopes / genetics
  • Immunodominant Epitopes / metabolism
  • Legionella pneumophila / pathogenicity
  • Legionella pneumophila / physiology*
  • Legionnaires' Disease / immunology*
  • Legionnaires' Disease / prevention & control
  • Lung / immunology*
  • Lung / microbiology
  • Mice
  • Mice, Inbred BALB C
  • Peptidylprolyl Isomerase / genetics
  • Recombinant Proteins / genetics
  • Virulence Factors / genetics


  • Antigens, Bacterial
  • Bacterial Proteins
  • Bacterial Vaccines
  • Immunodominant Epitopes
  • PILE protein, Legionella pneumophila
  • Recombinant Proteins
  • Virulence Factors
  • Flagellin
  • flaA protein, bacteria
  • Mip protein, Legionella pneumophila
  • Peptidylprolyl Isomerase