Blockade of CD47 ameliorates autoimmune inflammation in CNS by suppressing IL-1-triggered infiltration of pathogenic Th17 cells

J Autoimmun. 2016 May;69:74-85. doi: 10.1016/j.jaut.2016.03.002. Epub 2016 Mar 16.

Abstract

The migration of Th17 cells into central nervous system (CNS) tissue is the key pathogenic step in experimental autoimmune encephalomyelitis (EAE) model. However, the mechanism underlying the pathogenic Th17 cell migration remains elusive. Here we report that blockade of CD47 with CD47-Fc fusion protein is effective in preventing and curing EAE by impairing infiltration of Th17 cells into CNS. However, CD47 deficiency does not directly impair the migration of Th17 cells. Mechanistic studies showed that CD47 deficiency inhibited degradation of inducible nitric oxide synthase (iNOS) in proteasome of macrophages by Src activation and led to the increased nitric oxide (NO) production. Then NO suppressed inflammasome activation-induced IL-1β production. This lower IL-1β reduces the expression of IL-1R1 and migration-related chemokine receptors on CD47(-/-) Th17 cells, inhibiting the ability of Th17 cells to infiltrate into the CNS of CD47(-/-) mice and therefore suppressing EAE development. In vivo administration of exogenous IL-1β indeed promoted the infiltration CD47(-/-) Th17 cells into CNS and antagonized the protective role of CD47 deficiency in EAE pathogenesis. Our results demonstrate a potential preventive and therapeutic application of CD47 blockade in controlling EAE development.

Keywords: CD47; Cell infiltration; EAE; IL-1β; Th17 cells; iNOS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Blocking / pharmacology
  • Antibodies, Monoclonal / pharmacology
  • Autoimmunity*
  • Bone Marrow Cells
  • CD47 Antigen / genetics
  • CD47 Antigen / metabolism*
  • Cell Movement / genetics
  • Cell Movement / immunology
  • Disease Models, Animal
  • Encephalomyelitis, Autoimmune, Experimental / genetics
  • Encephalomyelitis, Autoimmune, Experimental / immunology*
  • Encephalomyelitis, Autoimmune, Experimental / metabolism*
  • Encephalomyelitis, Autoimmune, Experimental / pathology
  • Immunoglobulin Fc Fragments / genetics
  • Interleukin-1 / metabolism*
  • Macrophages / immunology
  • Macrophages / metabolism
  • Mice
  • Mice, Knockout
  • Multiple Sclerosis / genetics
  • Multiple Sclerosis / immunology
  • Multiple Sclerosis / metabolism
  • Multiple Sclerosis / pathology
  • Nitric Oxide Synthase Type II / metabolism
  • Proteasome Endopeptidase Complex / metabolism
  • Recombinant Fusion Proteins
  • T-Lymphocyte Subsets / immunology
  • T-Lymphocyte Subsets / metabolism
  • Th17 Cells / immunology*
  • Th17 Cells / metabolism*
  • src-Family Kinases / metabolism

Substances

  • Antibodies, Blocking
  • Antibodies, Monoclonal
  • CD47 Antigen
  • Immunoglobulin Fc Fragments
  • Interleukin-1
  • Recombinant Fusion Proteins
  • Nitric Oxide Synthase Type II
  • src-Family Kinases
  • Proteasome Endopeptidase Complex