Ameloblasts are specialized epithelial cells in the jaw that have an indispensable role in tooth enamel formation-amelogenesis1. Amelogenesis depends on multiple ameloblast-derived proteins that function as a scaffold for hydroxyapatite crystals. The loss of function of ameloblast-derived proteins results in a group of rare congenital disorders called amelogenesis imperfecta2. Defects in enamel formation are also found in patients with autoimmune polyglandular syndrome type-1 (APS-1), caused by AIRE deficiency3,4, and in patients diagnosed with coeliac disease5-7. However, the underlying mechanisms remain unclear. Here we show that the vast majority of patients with APS-1 and coeliac disease develop autoantibodies (mostly of the IgA isotype) against ameloblast-specific proteins, the expression of which is induced by AIRE in the thymus. This in turn results in a breakdown of central tolerance, and subsequent generation of corresponding autoantibodies that interfere with enamel formation. However, in coeliac disease, the generation of such autoantibodies seems to be driven by a breakdown of peripheral tolerance to intestinal antigens that are also expressed in enamel tissue. Both conditions are examples of a previously unidentified type of IgA-dependent autoimmune disorder that we collectively name autoimmune amelogenesis imperfecta.

• MeSH
• ameloblasty metabolismus   MeSH
• amelogenesis imperfecta * komplikace   imunologie   MeSH
• antigeny imunologie   metabolismus   MeSH
• autoimunitní polyglandulární syndromy * komplikace   imunologie   MeSH
• autoprotilátky * imunologie   MeSH
• celiakie * komplikace   imunologie   MeSH
• imunoglobulin A imunologie   MeSH
• lidé MeSH
• protein AIRE nedostatek   MeSH
• proteiny imunologie   metabolismus   MeSH
• střeva imunologie   metabolismus   MeSH
• zubní sklovina imunologie   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Patients with autoimmune polyendocrinopathy syndrome type 1 (APS-1) caused by autosomal recessive AIRE deficiency produce autoantibodies that neutralize type I interferons (IFNs)1,2, conferring a predisposition to life-threatening COVID-19 pneumonia3. Here we report that patients with autosomal recessive NIK or RELB deficiency, or a specific type of autosomal-dominant NF-κB2 deficiency, also have neutralizing autoantibodies against type I IFNs and are at higher risk of getting life-threatening COVID-19 pneumonia. In patients with autosomal-dominant NF-κB2 deficiency, these autoantibodies are found only in individuals who are heterozygous for variants associated with both transcription (p52 activity) loss of function (LOF) due to impaired p100 processing to generate p52, and regulatory (IκBδ activity) gain of function (GOF) due to the accumulation of unprocessed p100, therefore increasing the inhibitory activity of IκBδ (hereafter, p52LOF/IκBδGOF). By contrast, neutralizing autoantibodies against type I IFNs are not found in individuals who are heterozygous for NFKB2 variants causing haploinsufficiency of p100 and p52 (hereafter, p52LOF/IκBδLOF) or gain-of-function of p52 (hereafter, p52GOF/IκBδLOF). In contrast to patients with APS-1, patients with disorders of NIK, RELB or NF-κB2 have very few tissue-specific autoantibodies. However, their thymuses have an abnormal structure, with few AIRE-expressing medullary thymic epithelial cells. Human inborn errors of the alternative NF-κB pathway impair the development of AIRE-expressing medullary thymic epithelial cells, thereby underlying the production of autoantibodies against type I IFNs and predisposition to viral diseases.

• MeSH
• aktivační mutace MeSH
• autoprotilátky * imunologie   MeSH
• COVID-19 genetika   imunologie   MeSH
• epiteliální buňky štítné žlázy metabolismus   patologie   MeSH
• genetická predispozice k nemoci * MeSH
• heterozygot MeSH
• interferon typ I * antagonisté a inhibitory   imunologie   MeSH
• kinasa indukující NF-kappaB MeSH
• lidé MeSH
• mutace ztráty funkce MeSH
• NF-kappa B - podjednotka p52 nedostatek   genetika   MeSH
• NF-kappa B * nedostatek   genetika   MeSH
• protein AIRE MeSH
• proteiny I-kappa B nedostatek   genetika   MeSH
• thymus abnormality   imunologie   patologie   MeSH
• virová pneumonie genetika   imunologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH