Immunodeficiency, autoimmunity, and increased risk of B cell malignancy in humans with TRAF3 mutations

Sci Immunol. 2022 Aug 12;7(74):eabn3800. doi: 10.1126/sciimmunol.abn3800. Epub 2022 Aug 12.


Tumor necrosis factor receptor-associated factor 3 (TRAF3) is a central regulator of immunity. TRAF3 is often somatically mutated in B cell malignancies, but its role in human immunity is not defined. Here, in five unrelated families, we describe an immune dysregulation syndrome of recurrent bacterial infections, autoimmunity, systemic inflammation, B cell lymphoproliferation, and hypergammaglobulinemia. Affected individuals each had monoallelic mutations in TRAF3 that reduced TRAF3 expression. Immunophenotyping showed that patients' B cells were dysregulated, exhibiting increased nuclear factor-κB 2 activation, elevated mitochondrial respiration, and heightened inflammatory responses. Patients had mild CD4+ T cell lymphopenia, with a reduced proportion of naïve T cells but increased regulatory T cells and circulating T follicular helper cells. Guided by this clinical phenotype, targeted analyses demonstrated that common genetic variants, which also reduce TRAF3 expression, are associated with an increased risk of B cell malignancies, systemic lupus erythematosus, higher immunoglobulin levels, and bacterial infections in the wider population. Reduced TRAF3 conveys disease risks by driving B cell hyperactivity via intrinsic activation of multiple intracellular proinflammatory pathways and increased mitochondrial respiration, with a likely contribution from dysregulated T cell help. Thus, we define monogenic TRAF3 haploinsufficiency syndrome and demonstrate how common TRAF3 variants affect a range of human diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Autoimmunity / genetics
  • B-Lymphocytes
  • Humans
  • Mutation
  • Neoplasms* / pathology
  • TNF Receptor-Associated Factor 3* / genetics
  • TNF Receptor-Associated Factor 3* / metabolism


  • TNF Receptor-Associated Factor 3
  • TRAF3 protein, human