Autoantigen TRIM21/Ro52 is expressed on the surface of antigen-presenting cells and its enhanced expression in Sjögren’s syndrome is associated with B cell hyperactivity and type I interferon activity

Tripartite motif-containing protein 21 ( TRIM21 )/Ro52 is an immunoglobulin receptor that together with Ro60 makes up Sjogren’s syndrome-antigen A (SSA). A 60%–80% of patients with primary Sjogren’s syndrome (pSS) have anti-SSA autoantibodies and they form part of the pSS diagnosis. TRIM21 is a cytosolic Fc-receptor that mediates neutralisation of opsonised viruses and other particles, acting as a last line of defence against viruses that are...