Bacterial Quorum Sensing Molecule Induces Chemotaxis of Human Neutrophils via Induction of p38 and Leukocyte Specific Protein 1 (LSP1)

  • chair:

    Kahle, N. / Brenner-Weiss, G. / Overhag, J. / Obst, U. / Hänsch, G. (2013)
  • place:

    Immunobiology 2 (2013), 218, 145-51
  • Date: 2013

  • Kahle, N. / Brenner-Weiss, G. / Overhag, J. / Obst, U. / Hänsch, G. (2013): „Bacterial Quorum Sensing Molecule Induces Chemotaxis of Human Neutrophils via Induction of p38 and Leukocyte Specific Protein 1 (LSP1)“. In: Immunobiology 2 (2013), 218, 145-51

Abstract

When bacteria colonize surfaces, they socialize and form biofilms. This process is well regulated and relies on the communication among the bacteria via so-called “quorum sensing molecules”. Among those, N-(3-oxododecanoyl)-l-homoserine lactone (AHL-12), generated by Pseudomonas aeruginosa and other Gram-negative bacteria, activates not only bacteria but also interacts with mammalian cells. Among others, it activates phagocytic cells and – as we had shown previously – it is chemotactic for human polymorphonuclear neutrophils (PMN) in vitro.

In the present study, we analyzed the signalling pathway of AHL-12 in PMN. We focused on the mitogen activated protein (MAP) kinase p38, because SB203580, an inhibitor of p38, prevented the AHL-12 induced chemotaxis. We found that in response to AHL-12, p38 was phosphorylated within minutes, as was its downstream target, the MAPKAP-Kinase-2 (MK2). In PMN, the major substrate of MK2 is the leukocyte specific protein 1 (LSP1), which binds to F-actin and participates directly in actin polymerization and cell migration. In response to AHL-12, LSP1 was phosphorylated and co-localized with F-actin in polarized PMN, suggesting that AHL-12-induced migration depended on p38 and LSP1 activation.

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