Similarities and differences between selective and nonselective BAFF blockade in murine SLE

Area of Science:

• Immunology
• Autoimmunity
• Therapeutic Development

Background:

• B cells play crucial roles in immune activation and inflammation beyond antibody production.
• B cell depletion is a promising therapeutic strategy for autoimmune diseases.
• B cell-activating factor (BAFF) and A proliferation-inducing ligand (APRIL) are key regulators of B cell survival and differentiation.

Purpose of the Study:

• To compare the therapeutic effects of blocking BAFF alone versus blocking both BAFF and APRIL in a murine model of systemic lupus erythematosus (SLE).

Main Methods:

• Comparison of BAFF receptor-Ig (blocks BAFF) and transmembrane activator and calcium modulator ligand interactor-Ig (blocks BAFF and APRIL) in NZB/W F1 mice.
• Assessment of survival, B cell populations, T cell activation, dendritic cell accumulation, and antibody responses (IgG anti-dsDNA, IgM).

Main Results:

• Both BAFF blockade and BAFF/APRIL blockade prolonged survival and reduced B cell populations and T cell activation.
• Neither reagent significantly affected the IgG anti-double-stranded DNA response.
• Blockade of both BAFF and APRIL, unlike BAFF blockade alone, reduced IgM antibody levels, splenic plasma cells, and T cell-dependent IgM responses.

Conclusions:

• Blocking both BAFF and APRIL offers distinct advantages over BAFF blockade alone, particularly in reducing IgM production and plasma cell frequency.
• These findings have implications for selecting targeted therapies for autoimmune and malignant diseases.