Lipid-containing mimetics of natural triggers of innate immunity as CTL-inducing influenza vaccines

Int Immunol. 2006 Dec;18(12):1801-13. doi: 10.1093/intimm/dxl114. Epub 2006 Oct 31.

Abstract

Anti-viral CD8(+) T cell responses can be induced using synthetic lipopeptides and a range of different lipid moieties have been examined in a variety of model systems and in man for this purpose. Nevertheless, only limited data exist on comparative efficacy of different lipopeptides in a single model of protection so that the optimal composition for vaccination purposes remains unknown. In this study, we examined different lipid structures from bacterial or non-bacterial sources coupled to peptides representing influenza viral epitopes recognized by CD8(+) and CD4(+) T cells. These were assessed in the context of intra-nasal (i.n.) immunization in the absence of added adjuvant. The strongest immunogens were those containing bacterially derived lipids that induced dendritic cell (DC) maturation via Toll-like receptor 2 (TLR2) binding. The number of DCs induced to mature in vitro was directly associated with the strength of the CD8(+) T cell-mediated viral clearing responses in primed mice. Mice immunized with the TLR2-binding lipopeptides showed greatly enhanced numbers of specific IFN-gamma-secreting CD8(+) T cells at the site of infection after i.n. exposure to virus, which resulted in enhanced protection of the pneumonic lung. Importantly, lipopeptide-pulsed DCs were able to induce the appropriate T cells, indicating that the self-adjuvanting effects could occur in the absence of free lipopeptide interacting with additional TLR2-bearing cells in vivo. This study defines a hierarchy of lipopeptide constructs that can program DC to prime memory CD8(+) T cells that on recall function to clear influenza virus from the infected lung.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Biomimetics*
  • Female
  • Humans
  • Immunity, Innate*
  • Immunization
  • Influenza A Virus, H1N1 Subtype / genetics
  • Influenza A Virus, H1N1 Subtype / pathogenicity
  • Influenza A Virus, H3N2 Subtype / genetics
  • Influenza A Virus, H3N2 Subtype / pathogenicity
  • Influenza Vaccines / administration & dosage
  • Influenza Vaccines / chemistry
  • Influenza Vaccines / immunology*
  • Influenza, Human / immunology
  • Influenza, Human / prevention & control
  • Influenza, Human / virology
  • Lipoproteins* / administration & dosage
  • Lipoproteins* / chemical synthesis
  • Lipoproteins* / chemistry
  • Lipoproteins* / immunology
  • Lung / immunology
  • Lymphocyte Activation*
  • Mice
  • Mice, Inbred BALB C
  • Molecular Sequence Data
  • Peptides / administration & dosage
  • Peptides / chemical synthesis
  • Peptides / chemistry
  • Peptides / immunology
  • Reassortant Viruses / genetics
  • Reassortant Viruses / pathogenicity
  • T-Lymphocytes, Cytotoxic / immunology*

Substances

  • Influenza Vaccines
  • Lipoproteins
  • Peptides