Immunodeficiency, autoimmunity, and increased risk of B cell malignancy in humans with mutations.
Science immunology 2022 ; 7: eabn3800.
Rae W, Sowerby JM, Verhoeven D, Youssef M, Kotagiri P, Savinykh N, Coomber EL, Boneparth A, Chan A, Gong C, Jansen MH, du Long R, Santilli G, Simeoni I, Stephens J, Wu K, Zinicola M, Allen HL, Baxendale H, Kumararatne D, Gkrania-Klotsas E, Scheffler Mendoza SC, Yamazaki-Nakashimada MA, Ruiz LB, Rojas-Maruri CM, Lugo Reyes SO, Lyons PA, Williams AP, Hodson DJ, Bishop GA, Thrasher AJ, Thomas DC, Murphy MP, Vyse TJ, Milner JD, Kuijpers TW, Smith KGC
PubMed ID : 35960817
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 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 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 haploinsufficiency syndrome and demonstrate how common variants affect a range of human diseases.