Opposing roles of endothelial and leukocyte-expressed IL-7Rα in the regulation of psoriasis-like skin inflammation

Sci Rep. 2019 Aug 12;9(1):11714. doi: 10.1038/s41598-019-48046-y.

Abstract

The interleukin 7 receptor alpha chain (IL-7Rα) is predominately expressed by lymphocytes, and activation by its ligand IL-7 supports the development and maintenance of T cells and boosts T-cell mediated immunity. We recently reported that lymphatic endothelial cells (LECs) in dermal lymphatics also express IL-7 and its receptor chains (IL-7Rα and CD132) and that IL-7 supports lymphatic drainage. This suggested that activation of IL-7Rα signaling in lymphatics could exert inflammation-resolving activity, by promoting the clearance of excess tissue fluid. Here we investigated how the potentially opposing effects of IL-7Rα signaling in immune cells and in the lymphatic vasculature would affect the development and progression of psoriasis-like skin inflammation. We found that during acute and chronic skin inflammation mice with an endothelial-specific deletion of IL-7Rα (IL-7RαΔEC mice) developed more edema compared to control mice, as a consequence of impaired lymphatic drainage. However, systemic treatment of wild-type mice with IL-7 exacerbated edema and immune cell infiltration in spite of increasing lymphatic drainage, whereas treatment with IL-7Rα blocking antibody ameliorated inflammatory symptoms. These data identify IL-7Rα signaling as a new pathway in psoriasis-like skin inflammation and show that its pro-inflammatory effects on the immune compartment override its anti-inflammatory, drainage-enhancing effects on the endothelium.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Neutralizing / pharmacology*
  • CD4-Positive T-Lymphocytes / drug effects
  • CD4-Positive T-Lymphocytes / immunology*
  • CD4-Positive T-Lymphocytes / pathology
  • Disease Models, Animal
  • Endothelial Cells / drug effects
  • Endothelial Cells / immunology*
  • Endothelial Cells / pathology
  • Female
  • Gene Expression Regulation
  • Humans
  • Imiquimod / administration & dosage
  • Inflammation
  • Interleukin-7 / genetics
  • Interleukin-7 / immunology*
  • Lymph Nodes / drug effects
  • Lymph Nodes / immunology
  • Lymph Nodes / pathology
  • Lymphatic Vessels / drug effects
  • Lymphatic Vessels / immunology
  • Lymphatic Vessels / pathology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Organ Specificity
  • Oxazolone / administration & dosage
  • Psoriasis / chemically induced
  • Psoriasis / drug therapy*
  • Psoriasis / genetics
  • Psoriasis / pathology
  • Receptors, Interleukin-7 / antagonists & inhibitors
  • Receptors, Interleukin-7 / genetics
  • Receptors, Interleukin-7 / immunology*
  • Signal Transduction
  • Skin / drug effects
  • Skin / immunology*
  • Skin / pathology
  • Tetradecanoylphorbol Acetate / administration & dosage
  • Tetradecanoylphorbol Acetate / analogs & derivatives

Substances

  • Antibodies, Neutralizing
  • Interleukin-7
  • Receptors, Interleukin-7
  • interleukin-7 receptor, alpha chain
  • interleukin-7, mouse
  • Oxazolone
  • 4-O-methyl-12-O-tetradecanoylphorbol 13-acetate
  • Tetradecanoylphorbol Acetate
  • Imiquimod