Immune homeostasis in the gut-associated lymphoid tissues (GALT) is critical to prevent the development of inadvertent pathologies. B cells, as the producers of antibodies and cytokines, play an important role in maintaining the GALT homeostasis. However, the mechanism by which B cells specifically direct their responses toward non-self-antigens and become ignorant to self-antigens in the GALT is not known. Therefore, we developed what we believe to be a novel mouse model by expressing duck egg lysozyme (DEL) in gut epithelial cells in presence of HEL-reactive B cells. Notably, we observed a transient activation and rapid deletion of self-reactive B cells in Peyer’s patches and mesenteric lymph nodes upon self-antigen exposure. The survival of self-reactive B cells upon exposure to their self-antigen was partially rescued by blocking receptor editing but could be completely rescued by stronger survival signal, such as ectopic expression of BCL2. Importantly, rescuing the self-reactive B cells promoted production of autoantibodies and gut inflammation. Mechanistically, we identify a specific activation of TGF-β signaling in self-reactive B cells in the gut and a critical role of this pathway in maintaining peripheral tolerance. Collectively, our studies describe functional consequences and the fate of self-reactive B cells in GALT and provide potentially novel mechanistic insights governing self-tolerance of B cells in the gut.
Ashima Shukla, Cindi Chen, Julia Jellusova, Charlotte R. Leung, Elaine Kao, Numana Bhat, Wai W. Lin, John R. Apgar, Robert C. Rickert
Usage data is cumulative from July 2019 through April 2020.
Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.
Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.