Gene expression profiling in NOD mice reveals that B cells are highly educated by the pancreatic environment during autoimmune diabetes

Abstract

Aims/hypothesis B cells play an important role in driving the development of type 1 diabetes; however, it remains unclear how they contribute to local beta cell destruction during disease progression. Here, we use gene expression profiling of B cell subsets identified in inflamed pancreatic tissue to explore their primary functional role during the progression of autoimmune diabetes. Methods Transcriptional profiling was performed on FACS-sorted B cell subsets isolated from pancreatic islets and the pancreatic lymph nodes of NOD mice. Results B cells are highly modified by the inflamed pancreatic tissue and can be distinguished by their transcriptional profile from those in the lymph nodes. We identified both a discrete and a core shared gene expression profile in islet CD19+CD138– and CD19+CD138+ B cell subsets, the latter of which is known to have enriched autoreactivity during diabetes development. On localisation to pancreatic islets, compared with CD138– B cells, CD138+ B cells overexpress genes associated with adhesion molecules and growth factors. Their shared signature consists of gene expression changes related to the differentiation of antibody-secreting cells and gene regulatory networks associated with IFN signalling pathways, proinflammatory cytokines and Toll-like receptor (TLR) activation. Finally, abundant TLR7 expression was detected in islet B cells and was enhanced specifically in CD138+ B cells. Conclusions/interpretation Our study provides a detailed transcriptional analysis of islet B cells. Specific gene signatures and interaction networks have been identified that point towards a functional role for B cells in driving autoimmune diabetes. Graphical abstract

B cell metabolism in autoimmune diseases: signaling pathways and interventions

“…Increasing evidence supports the notion that B cell development, differentiation, function, and metabolism have significant impacts on the development of T1D ( 86 – 89 ). Nonobese diabetic (NOD) mice serve as an exceptional model for investigating type 1 diabetes in human ( 90 ). Studies have shown that NOD mice with B cell defects are protected from T1D development ( 91 ).…”