Receptor editing and genetic variability in human autoreactive B cells

Area of Science:

• Immunology
• Humanized Mouse Models

Background:

• B cell tolerance mechanisms like receptor editing, clonal deletion, and anergy are known in mice.
• Replicating these findings in humans has been difficult, hindering the understanding of human B cell tolerance.

Purpose of the Study:

• To investigate the mechanisms of central tolerance in autoreactive human B cells.
• To establish a novel humanized mouse model for studying human B cell tolerance.

Main Methods:

• Developed a humanized mouse model expressing a ubiquitous neo self-antigen (Ag).
• Transplanted mice with a human immune system to track self-reactive human B cells (κ+) versus nonautoreactive B cells (λ+).

Main Results:

• Human B cell tolerance occurs in the bone marrow upon initial self-antigen encounter.
• Tolerance is achieved through a combination of receptor editing and clonal deletion.
• Self-antigen availability and donor genetics influence central tolerance levels and peripheral autoreactive B cells.

Conclusions:

• The developed humanized mouse model effectively studies human B cell tolerance mechanisms.
• This model can reveal population-specific differences in B cell tolerance processes.
• Findings elucidate key pathways in preventing autoimmunity in humans.