The anti-microbial peptide LL-37 inhibits the activation of dendritic cells by TLR ligands. Academic Article uri icon

Overview

abstract

  • The endogenous anti-microbial peptide LL-37/hCAP-18 is an effector molecule of the innate host defense system at surfaces of the body. Besides its direct anti-microbial activity, the peptide interacts with different cell types. Dendritic cells (DCs) play a central role in mucosal host defense. It was the aim of the study to determine whether LL-37 modulates the response of DCs to pathogen-associated molecular patterns. Monocyte-derived DCs were stimulated with the Toll-like receptors (TLRs) ligands LPS, lipoteichoic acid and flagellin. We measured classical markers of DC maturation and assayed the ability of the DCs to activate T cell responses. Co-incubation with LL-37 resulted in suppressed activation of DCs. Levels of released IL-6, IL-12p70 and TNF-alpha and surface expression of HLA-DR, CD80, CD83, CD86 and the chemokine receptor CCR7 were decreased. Exposure of DCs to LL-37 during LPS exposure induced co-cultured naive T cells to produce less IL-2 and IFN-gamma and decreased their proliferation. The response of memory T cells to a recall antigen was also decreased. In conclusion, we demonstrate that the anti-microbial peptide LL-37 inhibits the activation of DCs by TLR ligands. We propose that LL-37 is a regulator of host defense responses at the intersection of innate and adaptive immune systems.

publication date

  • October 13, 2006

Research

keywords

  • Antimicrobial Cationic Peptides
  • Dendritic Cells
  • Ligands
  • Toll-Like Receptors

Identity

Scopus Document Identifier

  • 33845364149

Digital Object Identifier (DOI)

  • 10.1093/intimm/dxl107

PubMed ID

  • 17041145

Additional Document Info

volume

  • 18

issue

  • 12