TLR9 signalling in HCV-associated atypical memory B cells triggers Th1 and rheumatoid factor autoantibody responses

•TLR9 activation of atypical memory B cells (AtM) has a central role in breaking tolerance in patients with HCV-CV. •TLR9 signaling on AtMs stimulates proliferation and activation of effector Th1 cells by secreting TNFα. •Rheumatoid factors produced by AtMs recognized distinct IgG-Fc epitopes and did not cross-react against HCV proteins. •AtMs largely disappear after antigen removal by DAA therapy. Background & Aims Hepatitis C virus (HCV)...