c-Rel gain in B cells drives germinal center reactions and autoantibody production
Maike Kober-Hasslacher, Hyunju Oh-Strauß, Dilip Kumar, Valeria Soberon, Carina Diehl, Maciej Lech, Thomas Engleitner, Eslam Katab, Vanesa Fernández‐Sáiz, Guido Piontek, Hongwei Li, Bjoern Menze, Christoph Ziegenhain, Wolfgang Enard, Roland Rad, Jan P. Böttcher, Hans‐Joachim Anders, Martina Rudelius, Marc Schmidt‐Supprian
Abstract
Single-nucleotide polymorphisms and locus amplification link the NF-κB transcription factor c-Rel to human autoimmune diseases and B cell lymphomas, respectively. However, the functional consequences of enhanced c-Rel levels remain enigmatic. Here, we overexpressed c-Rel specifically in mouse B cells from BAC-transgenic gene loci and demonstrate that c-Rel protein levels linearly dictated expansion of germinal center B (GCB) cells and isotype-switched plasma cells. c-Rel expression in B cells of otherwise c-Rel-deficient mice fully rescued terminal B cell differentiation, underscoring its critical B cell-intrinsic roles. Unexpectedly, in GCB cells transcription-independent regulation produced the highest c-Rel protein levels among B cell subsets. In c-Rel-overexpressing GCB cells this caused enhanced nuclear translocation, a profoundly altered transcriptional program, and increased proliferation. Finally, we provide a link between c-Rel gain and autoimmunity by showing that c-Rel overexpression in B cells caused autoantibody production and renal immune complex deposition.