Defects in antigen-specific immune tolerance in continuous B cell lines from autoimmune mice

Area of Science:

• Immunology
• Autoimmunity
• Cell Biology

Background:

• Systemic lupus erythematosus (SLE) is characterized by B cell hyperactivity and impaired tolerance.
• Studying B cell defects in SLE is challenging due to difficulties in isolating pure B cells.
• Continuous B cell lines offer a model to investigate intrinsic B cell abnormalities.

Purpose of the Study:

• To investigate intrinsic B cell defects in autoimmunity using specific B cell lines.
• To assess the tolerance induction capacity of B cells from autoimmune-prone mice.

Main Methods:

• Developed continuous B lymphocyte cell lines specific for dinitrophenyl (DNP) from BWF1 (autoimmune) and BALB/c (control) mice.
• Assessed immune response kinetics to DNP-Ficoll.
• Tested tolerance induction using DNP-murine IgG2a (MGG) and trinitrophenyl-d-glutamyl lysine.

Main Results:

• BWF1 and BALB/c B cell lines showed similar immune response kinetics to DNP-Ficoll.
• BWF1 B cell lines required T cell-derived factors for immune response, similar to BALB/c cells.
• BWF1 B cell lines were resistant to tolerance induction by DNP-MGG, requiring 50-fold higher doses than BALB/c cells.

Conclusions:

• DNP-specific B cells from autoimmune mice possess an inherent defect in tolerance induction.
• This intrinsic B cell defect may contribute to the pathogenesis of systemic lupus erythematosus.
• B cell lines provide a valuable tool for studying autoimmune mechanisms.