PLoS ONE (Jan 2014)

Superior in vitro stimulation of human CD8+ T-cells by whole virus versus split virus influenza vaccines.

  • Benedict R Halbroth,
  • Alexander Heil,
  • Eva Distler,
  • Martin Dass,
  • Eva M Wagner,
  • Bodo Plachter,
  • Hans Christian Probst,
  • Dennis Strand,
  • Udo F Hartwig,
  • Anita Karner,
  • Gerald Aichinger,
  • Otfried Kistner,
  • Katharina Landfester,
  • Wolfgang Herr

DOI
https://doi.org/10.1371/journal.pone.0103392
Journal volume & issue
Vol. 9, no. 7
p. e103392

Abstract

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Pandemic and seasonal influenza viruses cause considerable morbidity and mortality in the general human population. Protection from severe disease may result from vaccines that activate antigen-presenting DC for effective stimulation of influenza-specific memory T cells. Special attention is paid to vaccine-induced CD8+ T-cell responses, because they are mainly directed against conserved internal influenza proteins thereby presumably mediating cross-protection against circulating seasonal as well as emerging pandemic virus strains. Our study showed that influenza whole virus vaccines of major seasonal A and B strains activated DC more efficiently than those of pandemic swine-origin H1N1 and pandemic-like avian H5N1 strains. In contrast, influenza split virus vaccines had a low ability to activate DC, regardless which strain was investigated. We also observed that whole virus vaccines stimulated virus-specific CD8+ memory T cells much stronger compared to split virus counterparts, whereas both vaccine formats activated CD4+ Th cell responses similarly. Moreover, our data showed that whole virus vaccine material is delivered into the cytosolic pathway of DC for effective activation of virus-specific CD8+ T cells. We conclude that vaccines against seasonal and pandemic (-like) influenza strains that aim to stimulate cross-reacting CD8+ T cells should include whole virus rather than split virus formulations.