GR-independent down-modulation on GM-CSF bone marrow-derived dendritic cells by the selective glucocorticoid receptor modulator Compound A

Sci Rep. 2016 Nov 18:6:36646. doi: 10.1038/srep36646.

Abstract

Dendritic cells (DC) initiate the adaptive immune response. Glucocorticoids (GCs) down-modulate the function of DC. Compound A (CpdA, (2-(4-acetoxyphenyl)-2-chloro-N-methyl-ethylammonium chloride) is a plant-derived GR-ligand with marked dissociative properties. We investigated the effects of CpdA on in vitro generated GM-CSF-conditioned bone marrow-derived DC (BMDC). CpdA-exposed BMDC exhibited low expression of cell-surface molecules and diminution of the release of proinflammatory cytokines upon LPS stimulation; processes associated with BMDC maturation and activation. CpdA-treated BMDC were inefficient at Ag capture via mannose receptor-mediated endocytosis and displayed reduced T-cell priming. CpdA prevented the LPS-induced rise in pErk1/2 and pP38, kinases involved in TLR4 signaling. CpdA fully inhibited LPS-induced pAktSer473, a marker associated with the generation of tolerogenic DC. We used pharmacological blockade and selective genetic loss-of-function tools and demonstrated GR-independent inhibitory effects of CpdA in BMDC. Mechanistically, CpdA-mediated inactivation of the NF-κB intracellular signaling pathway was associated with a short-circuiting of pErk1/2 and pP38 upstream signaling. Assessment of the in vivo function of CpdA-treated BMDC pulsed with the hapten trinitrobenzenesulfonic acid showed impaired cell-mediated contact hypersensitivity. Collectively, we provide evidence that CpdA is an effective BMDC modulator that might have a benefit for immune disorders, even when GR is not directly targeted.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetates / pharmacology*
  • Animals
  • B7-1 Antigen / metabolism
  • Bone Marrow Cells / cytology
  • Bone Marrow Cells / drug effects*
  • Dendritic Cells / cytology
  • Dendritic Cells / drug effects*
  • Down-Regulation*
  • Endocytosis / drug effects
  • Granulocyte-Macrophage Colony-Stimulating Factor / physiology*
  • Inflammation Mediators / antagonists & inhibitors
  • Lipopolysaccharides / pharmacology
  • Mice
  • Receptors, Glucocorticoid / drug effects*
  • Receptors, Glucocorticoid / metabolism*
  • Toll-Like Receptor 4 / drug effects
  • Toll-Like Receptor 4 / metabolism
  • Tyramine / analogs & derivatives*
  • Tyramine / pharmacology
  • Up-Regulation / drug effects

Substances

  • 2-(4-acetoxyphenyl)-2-chloro-N-methylethylamine
  • Acetates
  • B7-1 Antigen
  • Inflammation Mediators
  • Lipopolysaccharides
  • Receptors, Glucocorticoid
  • Tlr4 protein, mouse
  • Toll-Like Receptor 4
  • Granulocyte-Macrophage Colony-Stimulating Factor
  • Tyramine