Identification of the SLAM Adapter Molecule EAT-2 as a Lupus-Susceptibility Gene That Acts through Impaired Negative Regulation of Dendritic Cell Signaling

J Immunol. 2015 Nov 15;195(10):4623-31. doi: 10.4049/jimmunol.1500552. Epub 2015 Oct 2.


We showed previously that C57BL/6 congenic mice with an introgressed homozygous 70 cM (125.6 Mb) to 100 cM (179.8 Mb) interval on c1 from the lupus-prone New Zealand Black (NZB) mouse develop high titers of antinuclear Abs and severe glomerulonephritis. Using subcongenic mice, we found that a genetic locus in the 88-96 cM region was associated with altered dendritic cell (DC) function and synergized with T cell functional defects to promote expansion of pathogenic proinflammatory T cell subsets. In this article, we show that the promoter region of the NZB gene encoding the SLAM signaling pathway adapter molecule EWS-activated transcript 2 (EAT-2) is polymorphic, which results in an ∼ 70% reduction in EAT-2 in DC. Silencing of the EAT-2 gene in DC that lacked this polymorphism led to increased production of IL-12 and enhanced differentiation of T cells to a Th1 phenotype in T cell-DC cocultures, reproducing the phenotype observed for DC from congenic mice with the NZB c1 70-100 cM interval. SLAM signaling was shown to inhibit production of IL-12 by CD40L-activated DCs. Consistent with a role for EAT-2 in this inhibition, knockdown of EAT-2 resulted in increased production of IL-12 by CD40-stimulated DC. Assessment of downstream signaling following CD40 cross-linking in the presence or absence of SLAM cross-linking revealed that SLAM coengagement blocked activation of p38 MAPK and JNK signaling pathways in DC, which was reversed in DC with the NZB EAT-2 allele. We conclude that EAT-2 negatively regulates cytokine production in DC downstream of SLAM engagement and that a genetic polymorphism that disturbs this process promotes the development of lupus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / physiology*
  • Animals
  • Antibodies, Antinuclear / genetics
  • Antibodies, Antinuclear / immunology*
  • Base Sequence
  • CD40 Ligand / metabolism
  • Cell Differentiation / genetics
  • Cell Differentiation / immunology
  • Cells, Cultured
  • Coculture Techniques
  • Dendritic Cells / immunology*
  • Female
  • Interleukin-12 Subunit p35 / biosynthesis
  • JNK Mitogen-Activated Protein Kinases / metabolism
  • Lupus Erythematosus, Systemic / genetics*
  • Lupus Erythematosus, Systemic / immunology
  • Lymphocyte Activation / immunology
  • Mice
  • Mice, Inbred NZB
  • Molecular Sequence Data
  • RNA Interference
  • RNA, Small Interfering
  • Signal Transduction / immunology
  • Th1 Cells / cytology
  • Th1 Cells / immunology*
  • p38 Mitogen-Activated Protein Kinases / metabolism


  • Adaptor Proteins, Signal Transducing
  • Antibodies, Antinuclear
  • Il12a protein, mouse
  • Interleukin-12 Subunit p35
  • RNA, Small Interfering
  • Sh2d1b1 protein, mouse
  • CD40 Ligand
  • JNK Mitogen-Activated Protein Kinases
  • p38 Mitogen-Activated Protein Kinases