cells Review B Cell Activation and Escape of Tolerance Checkpoints: Recent Insights from Studying Autoreactive B Cells Carlo G. Bonasia 1 , Wayel H. Abdulahad 1,2 , Abraham Rutgers 1, Peter Heeringa 2 and Nicolaas A. Bos 1,* 1 Department of Rheumatology and Clinical Immunology, University Medical Center Groningen, University of Groningen, 9713 Groningen, GZ, The Netherlands;
[email protected] (C.G.B.);
[email protected] (W.H.A.);
[email protected] (A.R.) 2 Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, 9713 Groningen, GZ, The Netherlands;
[email protected] * Correspondence:
[email protected] Abstract: Autoreactive B cells are key drivers of pathogenic processes in autoimmune diseases by the production of autoantibodies, secretion of cytokines, and presentation of autoantigens to T cells. However, the mechanisms that underlie the development of autoreactive B cells are not well understood. Here, we review recent studies leveraging novel techniques to identify and characterize (auto)antigen-specific B cells. The insights gained from such studies pertaining to the mechanisms involved in the escape of tolerance checkpoints and the activation of autoreactive B cells are discussed. Citation: Bonasia, C.G.; Abdulahad, W.H.; Rutgers, A.; Heeringa, P.; Bos, In addition, we briefly highlight potential therapeutic strategies to target and eliminate autoreactive N.A. B Cell Activation and Escape of B cells in autoimmune diseases. Tolerance Checkpoints: Recent Insights from Studying Autoreactive Keywords: autoimmune diseases; B cells; autoreactive B cells; tolerance B Cells. Cells 2021, 10, 1190. https:// doi.org/10.3390/cells10051190 Academic Editor: Juan Pablo de 1.