AIRE-Deficient Patients Harbor Unique High-Affinity Disease-Ameliorating Autoantibodies

Summary

APS1/APECED patients are defined by defects in the autoimmune regulator (AIRE) that mediates central T cell tolerance to many self-antigens. AIRE deficiency also affects B cell tolerance, but this is incompletely understood. Here we show that most APS1/APECED patients displayed B cell autoreactivity toward unique sets of approximately 100 self-proteins. Thereby, autoantibodies from 81 patients collectively detected many thousands of human proteins. The loss of B cell tolerance seemingly occurred during antibody affinity maturation, an obligatorily T cell-dependent step. Consistent with this, many APS1/APECED patients harbored extremely high-affinity, neutralizing autoantibodies, particularly against specific cytokines. Such antibodies were biologically active in vitro and in vivo, and those neutralizing type I interferons (IFNs) showed a striking inverse correlation with type I diabetes, not shown by other anti-cytokine antibodies. Thus, naturally occurring human autoantibodies may actively limit disease and be of therapeutic utility.

Graphical Abstract

Highlights

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  Each AIRE-deficient patient has a private repertoire of autoantibody reactivities

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  Loss of B cell tolerance occurs during T cell-dependent somatic hypermutation

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  Patient autoantibodies have unprecedented affinities for conformational epitopes

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  Patient autoantibodies can display disease-ameliorating properties in vivo

Abstract

Self-reactive antibodies specific for type I interferons are associated with protection against type I diabetes in patients with an autoimmune syndrome caused by mutations in AIRE.