Temporal dynamics and genomic programming of plasma cell fates.

Area of Science:

• Immunology
• Cell Biology
• Genomics

Background:

• Plasma cells (PCs) are crucial for adaptive immunity, producing antibodies.
• The generation and developmental pathways of antigen-specific PC precursors are not fully understood.
• Germinal center (GC) responses generate affinity-matured PCs with varying lifespans.

Approach:

• Utilized a model antigen system to study PC precursor generation.
• Employed single-cell RNA sequencing (scRNA-seq) combined with B cell receptor sequencing (BCR-seq) in spleen and bone marrow.
• Conducted adoptive transfer experiments to validate findings.

Key Points:

• Demonstrated a biphasic generation of PC precursors during GC responses.
• Identified a novel PC transition state giving rise to functionally competent PC precursors.
• Discovered that clonal expansion of these precursors depends on inducible TIGIT expression.
• Observed preferential production of precursors for long-lived bone marrow PCs in the late GC phase.

Conclusions:

• Proposed a model for the proliferation and programming of long-lived PC precursors.
• This model involves extended antigen encounters followed by reduced antigen availability.
• Provides a framework for understanding the generation of long-term humoral immunity.