Development and migration of plasma cells in the mouse lymph node

Area of Science:

• Immunology
• Cell Biology
• Microscopy

Background:

• Plasma cell (PC) differentiation and migration are crucial for adaptive immunity.
• The precise migratory behaviors of nascent PCs within lymph nodes remain incompletely understood.
• Chemotaxis via Gαi-coupled receptors is a known driver of lymphocyte migration.

Purpose of the Study:

• To investigate the in vivo differentiation and migratory patterns of nascent plasma cells (PCs) in mouse lymph nodes.
• To elucidate the role of chemotaxis in pre-PC migration and localization.

Main Methods:

• Intravital microscopy was employed to visualize nascent PCs in live mouse lymph nodes.
• Pertussis toxin (Ptx) treatment was used to disrupt Gαi-coupled receptor signaling.
• In vitro assays assessed pre-PC locomotion on integrin ligand-coated surfaces.

Main Results:

• Pre-PCs exhibited random, long, linear migratory paths, distinct from other lymphocytes.
• Ptx treatment did not impede pre-PC movement but arrested other lymphocytes.
• Pre-PCs showed processive amoeboid locomotion in vitro, while differentiated PCs were arrested.
• PC differentiation and arrest predominantly occurred in the medullary cords.

Conclusions:

• Pre-PCs utilize a persistent random walk mechanism to navigate towards lymph node medullary cords.
• Localized chemokines in medullary cords appear to retain differentiating PCs.
• Chemotaxis is not the primary driver for initial pre-PC migration to the medullary cords.