Histone deacetylase inhibition modulates indoleamine 2,3-dioxygenase-dependent DC functions and regulates experimental graft-versus-host disease in mice

J Clin Invest. 2008 Jul;118(7):2562-73. doi: 10.1172/JCI34712.


Histone deacetylase (HDAC) inhibitors are antitumor agents that also have antiinflammatory properties. However, the mechanisms of their immunomodulatory functions are not known. We investigated the mechanisms of action of 2 HDAC inhibitors, suberoylanilide hydroxamic acid (SAHA) and ITF 2357, on mouse DC responses. Pretreatment of DCs with HDAC inhibitors significantly reduced TLR-induced secretion of proinflammatory cytokines, suppressed the expression of CD40 and CD80, and reduced the in vitro and in vivo allostimulatory responses induced by the DCs. In addition, injection of DCs treated ex vivo with HDAC inhibitors reduced experimental graft-versus-host disease (GVHD) in a murine allogeneic BM transplantation model. Exposure of DCs to HDAC inhibitors increased expression of indoleamine 2,3-dioxygenase (IDO), a suppressor of DC function. Blockade of IDO in WT DCs with siRNA and with DCs from IDO-deficient animals caused substantial reversal of HDAC inhibition-induced in vitro suppression of DC-stimulated responses. Direct injection of HDAC inhibitors early after allogeneic BM transplantation to chimeric animals whose BM-derived cells lacked IDO failed to protect from GVHD, demonstrating an in vivo functional role for IDO. Together, these data show that HDAC inhibitors regulate multiple DC functions through the induction of IDO and suggest that they may represent a novel class of agents to treat immune-mediated diseases.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, CD / metabolism
  • Bone Marrow Transplantation
  • Cytokines / metabolism
  • Dendritic Cells / drug effects
  • Dendritic Cells / physiology*
  • Dendritic Cells / transplantation
  • Enzyme Inhibitors / pharmacology*
  • Female
  • Gene Expression / drug effects
  • Graft vs Host Disease / pathology
  • Graft vs Host Disease / prevention & control*
  • Histone Deacetylase Inhibitors*
  • Humans
  • Hydroxamic Acids / pharmacology
  • Indoleamine-Pyrrole 2,3,-Dioxygenase / genetics
  • Indoleamine-Pyrrole 2,3,-Dioxygenase / metabolism*
  • Lipopolysaccharides / pharmacology
  • Lymphocyte Activation / drug effects
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C3H
  • Mice, Inbred C57BL
  • Mice, Inbred Strains
  • Mice, Knockout
  • RNA, Small Interfering / genetics
  • Survival Analysis
  • T-Lymphocytes / drug effects
  • T-Lymphocytes / immunology
  • T-Lymphocytes / metabolism
  • Vorinostat


  • Antigens, CD
  • Cytokines
  • Enzyme Inhibitors
  • Histone Deacetylase Inhibitors
  • Hydroxamic Acids
  • Indoleamine-Pyrrole 2,3,-Dioxygenase
  • Lipopolysaccharides
  • RNA, Small Interfering
  • Vorinostat
  • givinostat hydrochloride