Surface Ig variable domain glycosylation affects autoantigen binding and acts as threshold for human autoreactive B...

Area of Science:

• Immunology
• Glycobiology
• Structural Biology

Background:

• Rheumatoid arthritis (RA) is characterized by hallmark autoantibodies with variable domain glycans (VDGs).
• VDGs arise from N-linked glycosylation during somatic hypermutation and predict RA development.
• The functional impact of VDGs on autoreactive B cells is not well understood.

Purpose of the Study:

• To investigate the functional consequences of VDGs on human B cell biology.
• To elucidate the structural and binding characteristics of VDGs.
• To understand how VDGs contribute to autoimmune disease pathogenesis.

Main Methods:

• Crystallography to determine VDGs' structural position.
• Glycobiology techniques to analyze glycan structures.
• Functional B cell assays to assess B cell receptor dynamics and activation.
• Dynamic modeling to predict binding impacts.

Main Results:

• VDGs are located near the antigen-binding pocket of B cell receptors.
• VDGs increase the duration of B cell receptor presence on the cell surface.
• VDGs enhance B cell activation, suggesting a role in autoimmunity.

Conclusions:

• VDGs play a functional role in autoreactive B cell biology.
• The acquisition of VDGs can contribute to the breakdown of self-tolerance in RA.
• Understanding VDGs offers insights into autoimmune disease mechanisms.