Regulatory B Cells in Tumor Microenvironment

Regulatory B cells (Bregs) are integral to the tumor microenvironment (TME) and influence immune responses through the secretion of immunosuppressive cytokines such as IL-10, IL-35, and TGF-β. This review highlights recent findings on the phenotype and mechanisms of Bregs, emphasizing their dual role in regulating immune responses within the TME. Importantly, we further explored the latest advances in Breg regulatory mechanisms from the novel perspectives of epigenetics and metabolic remodeling, including the effects of DNA methylation, histone acetylation, glycolysis, and oxidative phosphorylation on Bregs. We also investigate the therapeutic targeting of Bregs, with a focus on STAT3 inhibitors such as lipoxin A4, cucurbitacins, and resveratrol, which show promising potential in mitigating the suppressive function of Bregs. Furthermore, this review provides a detailed analysis of the impact of Bregs on tumorigenesis and metastasis, emphasizing the importance of inhibiting specific immune pathways to prevent tumor escape. Finally, this review offers a prospective outlook on immunotherapy strategies based on Bregs, foreseeing a more nuanced understanding of their TME function and the evolution of targeted treatments with enhanced therapeutic efficacy.