Circulating human B cells that express surrogate light chains and edited receptors

Area of Science:

• Immunology
• Autoimmunity
• Molecular Biology

Background:

• Immunoglobulin gene recombination can produce self-reactive antibodies, which are normally silenced by deletion, anergy, or receptor editing.
• Receptor editing is a known mechanism for eliminating self-reactive B cells in mice, but identifying these cells in unmanipulated humans has been challenging.
• Autoimmune diseases like rheumatoid arthritis are characterized by the presence of autoantibodies.

Purpose of the Study:

• To identify and characterize human B cells that have undergone receptor editing.
• To investigate the potential role of these receptor-edited B cells in autoimmune diseases.

Main Methods:

• Isolation and characterization of B cells coexpressing surrogate and conventional light chains (V-preB+L+) from human blood.
• Analysis of RAG mRNA expression, antibody repertoire, and evidence of receptor editing in V-preB+L+ B cells.
• Examination of V-preB+L+ B cell accumulation in the joints of rheumatoid arthritis patients.

Main Results:

• V-preB+L+ B cells were identified in normal human donors.
• These cells express RAG mRNA and exhibit an unusual antibody repertoire suggestive of self-reactivity.
• Evidence of receptor editing was found in V-preB+L+ B cells.
• V-preB+L+ B cells were found to accumulate in the joints of patients with rheumatoid arthritis.

Conclusions:

• V-preB+L+ B cells represent a population of human B cells that have undergone receptor editing.
• The presence and accumulation of these cells in rheumatoid arthritis patients suggest a potential role in the pathogenesis of autoimmune disease.
• Further research into V-preB+L+ B cells and receptor editing could offer new insights into autoimmune disease mechanisms and potential therapeutic targets.