ORAI1 mutations abolishing store-operated Ca2+ entry cause anhidrotic ectodermal dysplasia with immunodeficiency - 05/10/18
Abstract |
Background |
Store-operated Ca2+ entry (SOCE) through Ca2+ release–activated Ca2+ channels is an essential signaling pathway in many cell types. Ca2+ release–activated Ca2+ channels are formed by ORAI1, ORAI2, and ORAI3 proteins and activated by stromal interaction molecule (STIM) 1 and STIM2. Mutations in the ORAI1 and STIM1 genes that abolish SOCE cause a combined immunodeficiency (CID) syndrome that is accompanied by autoimmunity and nonimmunologic symptoms.
Objective |
We performed molecular and immunologic analysis of patients with CID, anhidrosis, and ectodermal dysplasia of unknown etiology.
Methods |
We performed DNA sequencing of the ORAI1 gene, modeling of mutations on ORAI1 crystal structure, analysis of ORAI1 mRNA and protein expression, SOCE measurements, immunologic analysis of peripheral blood lymphocyte populations by using flow cytometry, and histologic and ultrastructural analysis of patient tissues.
Results |
We identified 3 novel autosomal recessive mutations in ORAI1 in unrelated kindreds with CID, autoimmunity, ectodermal dysplasia with anhidrosis, and muscular dysplasia. The patients were homozygous for p.V181SfsX8, p.L194P, and p.G98R mutations in the ORAI1 gene that suppressed ORAI1 protein expression and SOCE in the patients' lymphocytes and fibroblasts. In addition to impaired T-cell cytokine production, ORAI1 mutations were associated with strongly reduced numbers of invariant natural killer T and regulatory T (Treg) cells and altered composition of γδ T-cell and natural killer cell subsets.
Conclusion |
ORAI1 null mutations are associated with reduced numbers of invariant natural killer T and Treg cells that likely contribute to the patients' immunodeficiency and autoimmunity. ORAI1-deficient patients have dental enamel defects and anhidrosis, representing a new form of anhidrotic ectodermal dysplasia with immunodeficiency that is distinct from previously reported patients with anhidrotic ectodermal dysplasia with immunodeficiency caused by mutations in the nuclear factor κB signaling pathway (IKBKG and NFKBIA).
Le texte complet de cet article est disponible en PDF.Graphical abstract |
Key words : Ca2+ release–activated Ca2+ channel, store-operated Ca2+ entry, calcium, ORAI1, T cells, regulatory T cells, invariant natural killer T cells, immunodeficiency, combined immunodeficiency, anhidrotic ectodermal dysplasia
Abbreviations used : AIHA, ANA, AR, CID, CMV, CRAC, dOrai, EDA, EDA-ID, EM, ER, FOXP3, GAPDH, HD, H&E, HSCT, iNKT, IP3, NF-κB, NK, PAS, RSV, SOCE, STIM, TCR, TM, Treg, UCS
Plan
Supported by National Institutes of Health grants AI097302 (to S.F.), and AI065303 (to D.U.), postdoctoral fellowships KA 4514/1-1 (to S.K.) and VA 882/1-1 (to M.V.) by the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG), and BMBF grant 01 EO0803 by the German Federal Ministry of Education and Research (to S.E. and C.S.). |
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Disclosure of potential conflict of interest: I. Kacskovics is founder and CEO of ImmunoGenes and has the following patents: issued—European Union: EP 2 097 444 B1, Hong Kong: 2007323049, Australia: AU2007323049, Canada: CA2670389, China: CN101595128 A, and Japan: JP2010510773 (A); pending—USPTO: 12515586. S. Feske is a cofounder of Calcimedica and a coinventor on the following issued patent: WO/2007/081804. The rest of the authors declare that they have no relevant conflicts of interest. |
Vol 142 - N° 4
P. 1297 - octobre 2018 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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