TLR7 gain-of-function genetic variation causes human lupus.

TitleTLR7 gain-of-function genetic variation causes human lupus.
Publication TypeJournal Article
Year of Publication2022
AuthorsBrown GJ, Canete PF, Wang H, Medhavy A, Bones J, Roco JA, He Y, Qin Y, Cappello J, Ellyard JI, Bassett K, Shen Q, Burgio G, Zhang Y, Turnbull C, Meng X, Wu P, Cho E, Miosge LA, T Andrews D, Field MA, Tvorogov D, Lopez AF, Babon JJ, López CAparicio, Gónzalez-Murillo Á, Garulo DClemente, Pascual V, Levy T, Mallack EJ, Calame DG, Lotze T, Lupski JR, Ding H, Ullah TR, Walters GD, Koina ME, Cook MC, Shen N, Collantes Cde Lucas, Corry B, Gantier MP, Athanasopoulos V, Vinuesa CG
JournalNature
Date Published2022 Apr 27
ISSN1476-4687
Abstract

Although circumstantial evidence supports enhanced Toll-like receptor 7 (TLR7) signalling as a mechanism of human systemic autoimmune disease1-7, evidence of lupus-causing TLR7 gene variants is lacking. Here we describe human systemic lupus erythematosus caused by a TLR7 gain-of-function variant. TLR7 is a sensor of viral RNA8,9 and binds to guanosine10-12. We identified a de novo, previously undescribed missense TLR7Y264H variant in a child with severe lupus and additional variants in other patients with lupus. The TLR7Y264H variant selectively increased sensing of guanosine and 2',3'-cGMP10-12, and was sufficient to cause lupus when introduced into mice. We show that enhanced TLR7 signalling drives aberrant survival of B cell receptor (BCR)-activated B cells, and in a cell-intrinsic manner, accumulation of CD11c+ age-associated B cells and germinal centre B cells. Follicular and extrafollicular helper T cells were also increased but these phenotypes were cell-extrinsic. Deficiency of MyD88 (an adaptor protein downstream of TLR7) rescued autoimmunity, aberrant B cell survival, and all cellular and serological phenotypes. Despite prominent spontaneous germinal-centre formation in Tlr7Y264H mice, autoimmunity was not ameliorated by germinal-centre deficiency, suggesting an extrafollicular origin of pathogenic B cells. We establish the importance of TLR7 and guanosine-containing self-ligands for human lupus pathogenesis, which paves the way for therapeutic TLR7 or MyD88 inhibition.

DOI10.1038/s41586-022-04642-z
Custom 1

https://www.ncbi.nlm.nih.gov/pubmed/35477763?dopt=Abstract

Alternate JournalNature
PubMed ID35477763

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