Bacterial lipopolysaccharide activates CD57-negative human NK cells
- 80 Downloads
NK cells play an important regulatory role in sepsis by induction and augmentation of proinflammatory reactions in early stages of the septic process and by suppression of immune response in later stages of inflammation. The present work was aimed at the effect of bacterial lipopolysaccharide (LPS), the main pathogenic factor of sepsis development, on human NK cells ex vivo. We show that LPS activates immature CD57-negative NK cells, which typically constitute less than half of the normal NK cell population in human peripheral blood. Under conditions of NK cell stimulation with IL-2, addition of LPS provokes an increase in IFN-γ production. However, LPS both increased and inhibited NK cell cytotoxic activity. It is important to note that the activation of NK cells on LPS addition was observed in the absence of TLR4 on the NK cell surface. These results confirm our previous data arguing for a direct interaction of LPS with NK cells and evidence an atypical mechanism of LPS-induced NK cell activation without the involvement of surface TLR4.
Key wordsNK cells lipopolysaccharide IFN-γ production CD57 cytotoxicity TLR4
Unable to display preview. Download preview PDF.
- 1.Yarilin, A. A. (2010) Immunology [in Russian], GEOTAR-Media, Moscow.Google Scholar
- 4.Abakushina, E. V., Kuzmina, E. G., and Kovalenko, E. I. (2012) The main properties and functions of human NK cells, Immunologiya, 4, 220–225.Google Scholar
- 14.Saikh, K. U., Lee, J. S., Kissner, T. L., Dyas, B., and Ulrich, R. G. (2003) Toll-like receptor and cytokine expression patterns of CD56+ T cells are similar to natural killer cells in response to infection with Venezuelan equine encephalitis virus replicons, J. Infect. Dis., 188, 1562–1570.PubMedCrossRefGoogle Scholar
- 28.Lopez-Verges, S., Milush, J. M., Pandey, S., York, V. A., Arakawa-Hoyt, J., Pircher, H., Norris, P. J., Nixon, D. F., and Lanier, L. L. (2010) CD57 defines a functionally distinct population of mature NK cells in the human CD56dimCD16+ NK cell subset, Blood, 116, 3865–3874.PubMedCentralPubMedCrossRefGoogle Scholar
- 30.Kovalenko, E. I., Abakushina, E. V., Telford, W., Kapoor, V., Korchagina, E. Yu., Khaidukov, S. V., Molotkovskaya, I. M., Sapozhnikov, A. M., Vlaskin, P. A., and Bovin, N. V. (2007) Clustered carbohydrates as a target for natural killer cells: a model system, Histochem. Cell. Biol., 127, 313–326.PubMedCrossRefGoogle Scholar