Long-Lasting Cross-Protection Against Influenza A by Neuraminidase and M2e-based immunization strategies

Sci Rep. 2016 Apr 13:6:24402. doi: 10.1038/srep24402.

Abstract

There is mounting evidence that in the absence of neutralizing antibodies cross-reactive T cells provide protection against pandemic influenza viruses. Here, we compared protection and CD8+ T cell responses following challenge with H1N1 2009 pandemic and H3N2 viruses of mice that had been immunized with hemagglutinin (HA), neuraminidase (NA) and the extracellular domain of matrix protein 2 (M2e) fused to a virus-like particle (VLP). Mice were challenged a first time with a sublethal dose of H1N1 2009 pandemic virus and, four weeks later, challenged again with an H3N2 virus. Mice that had been vaccinated with HA, NA, NA + M2e-VLP and HA + NA + M2e-VLP were protected against homologous H1N1 virus challenge. Challenged NA and NA + M2e-VLP vaccinated mice mounted CD8+ T cell responses that correlated with protection against secondary H3N2 challenge. HA-vaccinated mice were fully protected against challenge with homologous H1N1 2009 virus, failed to mount cross-reactive CD8+ T cells and succumbed to the second challenge with heterologous H3N2 virus. In summary, NA- and M2e-based immunity can protect against challenge with (homologous) virus without compromising the induction of robust cross-reactive CD8+ T cell responses upon exposure to virus.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Neutralizing / immunology
  • CD8-Positive T-Lymphocytes / immunology
  • Cross Reactions
  • Female
  • Humans
  • Influenza A virus / immunology*
  • Influenza A virus / physiology
  • Influenza Vaccines / immunology
  • Influenza, Human / prevention & control*
  • Mice
  • Mice, Inbred BALB C
  • Neuraminidase / immunology*
  • Viral Matrix Proteins / immunology*
  • Virus Replication

Substances

  • Antibodies, Neutralizing
  • Influenza Vaccines
  • M2 protein, Influenza A virus
  • Viral Matrix Proteins
  • Neuraminidase