Characterization of structural and immunological properties of a fusion protein between flagellin from Salmonella and lumazine synthase from Brucella

Protein Sci. 2017 May;26(5):1049-1059. doi: 10.1002/pro.3151. Epub 2017 Mar 16.

Abstract

Aiming to combine the flexibility of Brucella lumazine synthase (BLS) to adapt different protein domains in a decameric structure and the capacity of BLS and flagellin to enhance the immunogenicity of peptides that are linked to their structure, we generated a chimeric protein (BLS-FliC131) by fusing flagellin from Salmonella in the N-termini of BLS. The obtained protein was recognized by anti-flagellin and anti-BLS antibodies, keeping the oligomerization capacity of BLS, without affecting the folding of the monomeric protein components determined by circular dichroism. Furthermore, the thermal stability of each fusion partner is conserved, indicating that the interactions that participate in its folding are not affected by the genetic fusion. Besides, either in vitro or in vivo using TLR5-deficient animals we could determine that BLS-FliC131 retains the capacity of triggering TLR5. The humoral response against BLS elicited by BLS-FliC131 was stronger than the one elicited by equimolar amounts of BLS + FliC. Since BLS scaffold allows the generation of hetero-decameric structures, we expect that flagellin oligomerization on this protein scaffold will generate a new vaccine platform with enhanced capacity to activate immune responses.

Keywords: BLS; TLR5; flagellin; scaffold.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brucella* / enzymology
  • Brucella* / genetics
  • Brucella* / immunology
  • Caco-2 Cells
  • Female
  • Flagellin* / biosynthesis
  • Flagellin* / genetics
  • Flagellin* / immunology
  • Humans
  • Immunity, Humoral
  • Mice
  • Mice, Knockout
  • Multienzyme Complexes* / biosynthesis
  • Multienzyme Complexes* / genetics
  • Multienzyme Complexes* / immunology
  • Recombinant Fusion Proteins* / biosynthesis
  • Recombinant Fusion Proteins* / genetics
  • Recombinant Fusion Proteins* / immunology
  • Salmonella typhimurium* / genetics
  • Salmonella typhimurium* / immunology
  • Salmonella typhimurium* / metabolism
  • Toll-Like Receptor 5 / genetics
  • Toll-Like Receptor 5 / immunology

Substances

  • Multienzyme Complexes
  • Recombinant Fusion Proteins
  • Toll-Like Receptor 5
  • Flagellin
  • 6,7-dimethyl-8-ribityllumazine synthase

Associated data

  • PDB/1T13
  • PDB/3A5X