Regulatory B cells: Phenotype, function and role in transplantation.

Area of Science:

• Immunology
• Transplantation immunology

Background:

• B cells traditionally known for antibody production, now recognized for regulatory functions (Bregs).
• Bregs share similarities with regulatory T cells (Tregs) and influence autoimmune diseases, infections, and malignancies.
• Bregs primarily exert regulatory functions through IL-10 secretion, promoting Tregs and suppressing effector T cells.

Purpose of the Study:

• To review the fundamental biology of Bregs, drawing parallels from autoimmunity and infectious disease research.
• To discuss the emerging and often controversial role of Bregs in solid organ transplantation, particularly kidney recipients.
• To highlight the current gaps in understanding Breg involvement in transplantation and suggest future research directions.

Main Methods:

• Literature review focusing on basic Breg biology from autoimmunity and infectious disease models.
• Analysis of existing studies on Bregs in the context of solid organ transplantation.
• Synthesis of findings to evaluate the relevance of Breg biology for transplantation.

Main Results:

• Bregs are crucial in immune homeostasis, primarily through IL-10 mediated suppression of effector T cells and promotion of Tregs.
• Evidence for Bregs in transplantation is limited and debated, with some studies suggesting improved graft survival.
• Fundamental Breg research predominantly stems from non-transplant fields, necessitating adaptation of knowledge.

Conclusions:

• Understanding basic Breg biology is essential for elucidating their role in transplantation.
• Further research is needed to clarify the precise mechanisms and impact of Bregs on graft survival and tolerance.
• Bregs represent a promising, yet understudied, area with potential therapeutic implications for transplant recipients.