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TLR7 gain-of-function genetic variation causes human lupus

ABSTRACT: While circumstantial evidence supports enhanced TLR7 signaling as a mechanism of human systemic autoimmune disease, we have lacked the proof afforded by lupus-causing TLR7 gene variants. Here we describe human systemic lupus erythematosus (SLE) caused by TLR7 gain-of-function (GoF). We identified a de novo, novel, missense TLR7 Y264H variant in a child with severe lupus. The de novo TLR7 Y264H variant selectively increased sensing of guanosine and was sufficient to cause lupus when introduced in mice (kika mice). We performed RNA-seq of kika and wild type B cells cultured for 20 hours with anti-IgM and found a decreased tendency to apoptosis in kika B cells, including decreased expression of active Caspase 3 and also a small decrease in proliferation. Overall, these results suggest that hypersensitive TLR7 signaling allows the survival of B cells that are binding self-antigen through their surface BCR.

ORGANISM(S): Mus musculus

PROVIDER: GSE196316 | GEO | 2022/02/10

REPOSITORIES: GEO

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