The NF-κB regulator MALT1 determines the encephalitogenic potential of Th17 cells

J Clin Invest. 2012 Dec;122(12):4698-709. doi: 10.1172/JCI63528. Epub 2012 Nov 1.

Abstract

Effector functions of inflammatory IL-17-producing Th (Th17) cells have been linked to autoimmune diseases such as experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis (MS). However, what determines Th17 cell encephalitogenicity is still unresolved. Here, we show that after EAE induction, mice deficient for the NF-κB regulator MALT1 (Malt1-/- mice) exhibit strong lymphocytic infiltration in the CNS, but do not develop any clinical signs of EAE. Loss of Malt1 interfered with expression of the Th17 effector cytokines IL-17 and GM-CSF both in vitro and in vivo. In line with their impaired GM-CSF secretion, Malt1-/- Th cells failed to recruit myeloid cells to the CNS to sustain neuroinflammation, whereas autoreactive WT Th cells successfully induced EAE in Malt1-/- hosts. In contrast, Malt1 deficiency did not affect Th1 cells. Despite their significantly decreased secretion of Th17 effector cytokines, Malt1-/- Th17 cells showed normal expression of lineage-specific transcription factors. Malt1-/- Th cells failed to cleave RelB, a suppressor of canonical NF-κB, and exhibited altered cellular localization of this protein. Our results indicate that MALT1 is a central, cell-intrinsic factor that determines the encephalitogenic potential of inflammatory Th17 cells in vivo.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Caspases / deficiency
  • Caspases / genetics*
  • Cell Differentiation
  • Cells, Cultured
  • Central Nervous System / pathology
  • Encephalomyelitis, Autoimmune, Experimental / immunology*
  • Encephalomyelitis, Autoimmune, Experimental / pathology
  • Granulocyte-Macrophage Colony-Stimulating Factor / metabolism
  • Interleukin-17 / metabolism
  • Interleukins / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein
  • NF-kappa B
  • Neoplasm Proteins / deficiency
  • Neoplasm Proteins / genetics*
  • Proteolysis
  • Th1 Cells / immunology
  • Th1 Cells / physiology
  • Th17 Cells / immunology
  • Th17 Cells / metabolism
  • Th17 Cells / physiology*
  • Transcription Factor RelB / metabolism
  • Transcription Factors / genetics
  • Transcription Factors / metabolism

Substances

  • Interleukin-17
  • Interleukins
  • NF-kappa B
  • Neoplasm Proteins
  • Relb protein, mouse
  • Transcription Factors
  • Transcription Factor RelB
  • Granulocyte-Macrophage Colony-Stimulating Factor
  • Caspases
  • Malt1 protein, mouse
  • Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein
  • interleukin-21
  • interleukin-22