Distinct metabolic requirements regulate B cell activation and germinal center responses

Area of Science:

• Immunology
• Cellular Metabolism
• Molecular Biology

Background:

• Activated B cells proliferate vigorously, utilizing aerobic glycolysis via lactate dehydrogenase A (LDHA).
• The precise role of LDHA in the metabolic transition of B cells from naïve to activated states is not well understood.

Purpose of the Study:

• To investigate the stage-specific and cell-specific roles of LDHA in B cell immune responses.
• To determine the metabolic requirements of naïve versus activated B cells during immune activation.

Main Methods:

• Stage-specific and cell-specific deletion of LDHA in B and T cells.
• Assessment of B cell proliferation, germinal center formation, and antibody responses following bacterial lipopolysaccharide stimulation.
• Analysis of immune responses in LDHA-deficient models.

Main Results:

• LDHA ablation in naïve B cells impaired germinal center formation and GC-dependent antibody responses but not extrafollicular responses.
• Loss of LDHA in T cells significantly compromised B cell-mediated immunity.
• Deleting LDHA in activated B cells had minimal impact on germinal center reactions and high-affinity antibody generation.

Conclusions:

• Naïve and activated B cells exhibit distinct metabolic dependencies on LDHA.
• LDHA is critical for GC-dependent B cell maturation and antibody production, but less so for activated B cells.
• Cellular context and interactions influence metabolic requirements during immune responses.