Regulatory B cells in the central nervous system: From immune regulation to neuroprotection

Abstract This review examines the immunoregulatory functions of interleukin‐10 (IL‐10)‐secreting regulatory B cells (Bregs), specifically focusing on their potential neuroprotective roles and therapeutic implications for central nervous system (CNS) disorders. We conducted a narrative review of the current literature to evaluate the defining characteristics, mechanisms of action, and functional significance of Bregs. We specifically analyzed their roles in modulating immune responses within the CNS following injury and in neurodegenerative contexts. Bregs are a distinct immunosuppressive B cell subset that operates primarily via IL‐10 secretion. Their functions include suppressing pro‐inflammatory cytokine production and directing T cell differentiation toward regulatory phenotypes. In CNS pathologies, evidence suggests that Bregs can infiltrate the blood–brain barrier following disruption. Once within the CNS, they exert neuroprotection and enhance neuronal survival, thereby mitigating post‐injury inflammation. Bregs are essential to immune regulation with significant, although not fully elucidated, neuroprotective potential. Their ability to modulate CNS makes them viable therapeutic targets for the treatment of brain injuries and neurodegenerative diseases. However, clinical applications must consider the complexities of B‐cell biology to avoid compromising immune homeostasis. Further research into Breg mechanisms is vital for developing safe, targeted therapies.