Enhanced influenza virus-like particle vaccines containing the extracellular domain of matrix protein 2 and a Toll-like receptor ligand

Clin Vaccine Immunol. 2012 Aug;19(8):1119-25. doi: 10.1128/CVI.00153-12. Epub 2012 May 30.

Abstract

The extracellular domain of matrix protein 2 (M2e) is conserved among influenza A viruses. The goal of this project is to develop enhanced influenza vaccines with broad protective efficacy using the M2e antigen. We designed a membrane-anchored fusion protein by replacing the hyperimmunogenic region of Salmonella enterica serovar Typhimurium flagellin (FliC) with four repeats of M2e (4.M2e-tFliC) and fusing it to a membrane anchor from influenza virus hemagglutinin (HA). The fusion protein was incorporated into influenza virus M1-based virus-like particles (VLPs). These VLPs retained Toll-like receptor 5 (TLR5) agonist activity comparable to that of soluble FliC. Mice immunized with the VLPs by either intramuscular or intranasal immunization showed high levels of systemic M2-specific antibody responses compared to the responses to soluble 4.M2e protein. High mucosal antibody titers were also induced in intranasally immunized mice. All intranasally immunized mice survived lethal challenges with live virus, while intramuscularly immunized mice showed only partial protection, revealing better protection by the intranasal route. These results indicate that a combination of M2e antigens and TLR ligand adjuvants in VLPs has potential for development of a broadly protective influenza A virus vaccine.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Administration, Intranasal
  • Animals
  • Antibodies, Viral / blood
  • Disease Models, Animal
  • Female
  • Flagellin / genetics
  • Flagellin / immunology*
  • Hemagglutinin Glycoproteins, Influenza Virus / genetics
  • Hemagglutinin Glycoproteins, Influenza Virus / immunology*
  • Immunity, Mucosal
  • Influenza Vaccines / administration & dosage
  • Influenza Vaccines / genetics
  • Influenza Vaccines / immunology*
  • Injections, Intramuscular
  • Ligands
  • Mice
  • Mice, Inbred BALB C
  • Orthomyxoviridae Infections / mortality
  • Orthomyxoviridae Infections / prevention & control
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / immunology
  • Salmonella typhimurium / genetics
  • Salmonella typhimurium / immunology
  • Survival Analysis
  • Toll-Like Receptor 5 / agonists*
  • Vaccines, Virosome / administration & dosage
  • Vaccines, Virosome / genetics
  • Vaccines, Virosome / immunology
  • Viral Matrix Proteins / genetics
  • Viral Matrix Proteins / immunology*

Substances

  • Antibodies, Viral
  • Hemagglutinin Glycoproteins, Influenza Virus
  • Influenza Vaccines
  • Ligands
  • M2 protein, Influenza A virus
  • Recombinant Fusion Proteins
  • Toll-Like Receptor 5
  • Vaccines, Virosome
  • Viral Matrix Proteins
  • Flagellin