c-Rel gain in B cells drives germinal center reactions and autoantibody production
Maike Kober-Hasslacher, … , Martina Rudelius, Marc Schmidt-Supprian
Maike Kober-Hasslacher, … , Martina Rudelius, Marc Schmidt-Supprian
Published March 19, 2020
Citation Information: J Clin Invest. 2020;130(6):3270-3286. https://doi.org/10.1172/JCI124382.
View: Text | PDF
Research Article Autoimmunity Immunology

c-Rel gain in B cells drives germinal center reactions and autoantibody production

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.

Authors

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, Björn Menze, Christoph Ziegenhain, Wolfgang Enard, Roland Rad, Jan P. Böttcher, Hans-Joachim Anders, Martina Rudelius, Marc Schmidt-Supprian

×

Figure 2

c-Rel gain enhances immune responses upon immunization.

Options: View larger image (or click on image) Download as PowerPoint
c-Rel gain enhances immune responses upon immunization. (A) CD95hiCD38lo...
(A) CD95hiCD38lo GCB and CD138+B220lo plasma cell numbers 10–12 days after SRBC immunizations obtained from 4 independent experiments. Bars and numbers below graphs are medians. *P ≤ 0.05, ***P ≤ 0.001, paired t test. (B) Areas of splenic GCs quantified based on Bcl6 immunofluorescence in 5 CD19CreI/+ and 5 RelTG CD19CreI/+ mice 10 days after SRBC immunizations (CD19CreI/+, n = 61; RelTG CD19CreI/+, n = 53). Bars and numbers below graphs are means. **P ≤ 0.01, unpaired t test. (C) Percentages of Ig subtypes in splenic plasma cells obtained by intracellular flow cytometry 10–12 days after SRBC immunization. Displayed medians include data from 6 mice from 2 independent experiments. **P ≤ 0.01, paired t test. (D) Individual anti-SRBC IgG1 titers analyzed by flow cytometry 10 days after immunization of 2 independent experiments. Bars and numbers below graphs are medians. (E) NP-CG–immunized mice analyzed after 14 days: Individual percentages of CD95hiCD38lo GCB and IgG+NP+ GCB cells within all splenic B cells are plotted. Bars and numbers below graphs are medians. *P < 0.05, unpaired t test. (F and G) Specific IgG1 serum titers measured by ELISA and calculated by absorbance summation (61) following NP-CG immunizations. Titers for NP2 (high affinity) and NP23 (high and low affinity) (F) and the NP2/NP23 ratio (G) are displayed from 2 independent immunizations. *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001, multiple t tests. (H) Affinity maturation 14 days after NP-CG immunizations analyzed by sequencing of IgG1 VH186.2 rearrangements in GCB cells for 2 independently immunized cohorts with 2 mice per genotype: 4 CD19CreI/+ mice: immunization I, n = 126 sequences; immunization II, n = 148 sequences; 4 RelTG CD19CreI/+ mice: immunization I, n = 122 sequences; immunization II, n = 117 sequences. The percentage of sequences with the VH186.2 W33L mutation is shown. SPL, spleen; Imm, immunized; ND, not determined. See Supplemental Figures 5 and 6.