TNF-α Limits Serological Memory by Disrupting the Bone Marrow Niche

Area of Science:

• Immunology
• Cell Biology

Background:

• Infection and autoimmune diseases can impair serological memory by disrupting antibody titers.
• The mechanisms behind diminished serological memory are not fully understood.

Purpose of the Study:

• To investigate the role of tumor necrosis factor-alpha (TNF-α) in regulating the plasma cell niche within the bone marrow.
• To elucidate the mechanisms by which inflammation affects antibody titers and serological memory.

Main Methods:

• Utilized recombinant TNF-α treatment in mice to observe effects on antibody titers and plasma cell retention.
• Employed bone marrow chimeric mice to study cell-extrinsic regulation of plasma cell egress.
• Analyzed plasma cell motility, egress, and survival following TNF-α signaling.

Main Results:

• Acute TNF-α treatment reduced pre-existing antibody titers by limiting plasma cell retention in the bone marrow.
• Mice lacking TNF-α signaling exhibited increased bone marrow plasma cell capacity and higher antibody titers.
• TNF-α signaling, via TNF-α receptor 1, promoted plasma cell egress from the bone marrow by increasing vascular permeability and downregulating CD138.
• TNF-α also inhibited plasma cell re-engraftment and survival in the bone marrow.

Conclusions:

• TNF-α is a key regulator of the plasma cell niche in the bone marrow.
• TNF-α-mediated inflammation attenuates serological memory durability by promoting plasma cell egress and reducing survival.
• Understanding TNF-α's role is crucial for managing antibody production and immune memory in various disease states.