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

Academic Article

Abstract

  • 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.

    • Authors

    Published In

    Keywords

  • Adenosine Deaminase Inhibitors, Animals, CD4-Positive T-Lymphocytes, Cells, Cultured, Colitis, Cytokines, Enzyme Inhibitors, Enzyme-Linked Immunosorbent Assay, Imidazoles, Interleukin-10, Lymphocyte Depletion, Lymphocyte Subsets, Mice, Mice, Inbred C57BL, Pentostatin, Polymerase Chain Reaction

    • Digital Object Identifier (doi)

    Author List

  • Brown JB; Lee G; Grimm GR; Barrett TA

    • Start Page

  • 880

    • End Page

  • 887

    • Volume

  • 14

    • Issue

  • 7