Klebsiella pneumoniae-triggered DC recruit human NK cells in a CCR5-dependent manner leading to increased CCL19-responsiveness and activation of NK cells

Eur J Immunol. 2010 Nov;40(11):3138-49. doi: 10.1002/eji.201040496. Epub 2010 Sep 24.


Besides their role in destruction of altered self-cells, NK cells have been shown to potentiate T-cell responses by interacting with DC. To take advantage of NK-DC crosstalk in therapeutic DC-based vaccination for infectious diseases and cancer, it is essential to understand the biology of this crosstalk. We aimed to elucidate the in vitro mechanisms responsible for NK-cell recruitment and activation by DC during infection. To mimic bacterial infection, DC were exposed to a membrane fraction of Klebsiella pneumoniae, which triggers TLR2/4. DC matured with these bacterial fragments can actively recruit NK cells in a CCR5-dependent manner. An additional mechanism of DC-induced NK-cell recruitment is characterized by the induction of CCR7 expression on CD56(dim) CD16(+) NK cells after physical contact with membrane fraction of K. pneumoniae-matured DC, resulting in an enhanced migratory responsiveness to the lymph node-associated chemokine CCL19. Bacterial fragment-matured DC do not only mediate NK-cell migration but also meet the prerequisites needed for augmentation of NK-cell cytotoxicity and IFN-γ production, the latter of which contributes to Th1 polarization.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Movement / immunology*
  • Cells, Cultured
  • Chemokine CCL19 / immunology*
  • Dendritic Cells / immunology*
  • Gene Expression Regulation / immunology
  • Humans
  • Interferon-gamma / immunology
  • Killer Cells, Natural / immunology*
  • Klebsiella Infections / immunology*
  • Klebsiella pneumoniae / immunology*
  • Lymphocyte Activation / immunology*
  • Receptors, CCR5 / immunology*
  • Receptors, CCR7 / immunology
  • Th1 Cells / immunology
  • Toll-Like Receptor 2 / immunology
  • Toll-Like Receptor 4 / immunology


  • CCL19 protein, human
  • CCR7 protein, human
  • Chemokine CCL19
  • Receptors, CCR5
  • Receptors, CCR7
  • TLR2 protein, human
  • TLR4 protein, human
  • Toll-Like Receptor 2
  • Toll-Like Receptor 4
  • Interferon-gamma