C9orf72 ablation causes immune dysregulation characterized by leukocyte expansion, autoantibody production, and glomerulonephropathy in mice

Sci Rep. 2016 Mar 16;6:23204. doi: 10.1038/srep23204.

Abstract

The expansion of a hexanucleotide (GGGGCC) repeat in C9ORF72 is the most common cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Both the function of C9ORF72 and the mechanism by which the repeat expansion drives neuropathology are unknown. To examine whether C9ORF72 haploinsufficiency induces neurological disease, we created a C9orf72-deficient mouse line. Null mice developed a robust immune phenotype characterized by myeloid expansion, T cell activation, and increased plasma cells. Mice also presented with elevated autoantibodies and evidence of immune-mediated glomerulonephropathy. Collectively, our data suggest that C9orf72 regulates immune homeostasis and an autoimmune response reminiscent of systemic lupus erythematosus (SLE) occurs in its absence. We further imply that haploinsufficiency is unlikely to be the causative factor in C9ALS/FTD pathology.

MeSH terms

  • Animals
  • Autoantibodies / biosynthesis*
  • Autoantibodies / blood
  • Autoimmunity*
  • C9orf72 Protein
  • Cytokines / blood
  • Female
  • Glomerulonephritis, Membranoproliferative / blood
  • Glomerulonephritis, Membranoproliferative / genetics*
  • Glomerulonephritis, Membranoproliferative / immunology
  • Guanine Nucleotide Exchange Factors / genetics*
  • Guanine Nucleotide Exchange Factors / metabolism
  • Lupus Erythematosus, Systemic / genetics
  • Lupus Erythematosus, Systemic / immunology
  • Lymphocyte Activation
  • Lymphoid Tissue / pathology
  • Macrophages / immunology
  • Male
  • Mice, 129 Strain
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Plasma Cells / immunology
  • Sequence Analysis, RNA
  • Transcriptome

Substances

  • Autoantibodies
  • C9orf72 Protein
  • C9orf72 protein, mouse
  • Cytokines
  • Guanine Nucleotide Exchange Factors