Therapeutic benefit of pentostatin in severe IL-10-/- colitis

Inflamm Bowel Dis. 2008 Jul;14(7):880-7. doi: 10.1002/ibd.20410.


Background: Pentostatin, an adenosine deaminase (ADA) inhibitor, is a purine antimetabolite used for the treatment of leukemias. ADA inhibition blunts expansion of proliferating lymphocytes and increases adenosine release, a potent anti-inflammatory molecule. Human inflammatory bowel disease (IBD) is driven by expansion of effector T cells (T(eff)) that overwhelm reulatory T cells (T(reg)) and propagate innate immune reponses. Here we study the therapeutic benefits of ADA inhibition to impair T(eff) cell expansion and reduce inflammatory cytokine release in IL-10-deficient (IL-10-/-) mice.

Methods: Colitis was induced in IL-10-/- mice by administering piroxicam for two weeks. Mice were treated with daily pentostatin or phosphate-buffered saline for 1 week and effects on tissue inflammation, lymphocyte numbers and cytokine production examined.

Results: Pentostatin reduced inflammation by >50% and nearly normalized serum amyloid A levels. Lymphocyte expansions in the colon and mesenteric lymph node (MLN) (3.5-fold and >5-fold respectively) dropped by >50-90%. Pro-inflammatory factors in the colon and MLN (IL-1beta, IFN-gamma, IL-6, CXCL10, TNF) dropped whereas FoxP3 and TGF-beta were unchanged. Reductions in cytokine production from equivalent numbers of T cells from pentostatin-treated mice after in vitro (36h) or in vivo (3h) activation suggested anti-inflammatory effects of pentostatin independent of lymphodepletion contributed to its therapeutic benefit. Analysis of mucosal lymphocyte subsets suggested pentostatin reduced numbers of effector CD4+ CD69+ T cells, while sparing CD4+ CD62L+ T cells.

Conclusions: Pentostatin dosages that avoid severe lymphocyte depletion effectively treat colitis by impairing T(eff) cell expansion and reducing pro-inflammatory cytokine production while preserving regulatory T(reg) populations and function.

Publication types

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

MeSH terms

  • Adenosine Deaminase Inhibitors*
  • Animals
  • CD4-Positive T-Lymphocytes / physiology
  • Cells, Cultured
  • Colitis / chemically induced
  • Colitis / drug therapy*
  • Colitis / immunology
  • Cytokines / biosynthesis
  • Enzyme Inhibitors / therapeutic use*
  • Enzyme-Linked Immunosorbent Assay
  • Imidazoles
  • Interleukin-10 / deficiency*
  • Lymphocyte Depletion
  • Lymphocyte Subsets / cytology
  • Mice
  • Mice, Inbred C57BL
  • Pentostatin / therapeutic use*
  • Polymerase Chain Reaction


  • Adenosine Deaminase Inhibitors
  • Cytokines
  • Enzyme Inhibitors
  • Imidazoles
  • Interleukin-10
  • piroximone
  • Pentostatin