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 germinal center (GC) reaction generates affinity-matured B cells, including PCs of varying lifespans.
• The precise developmental pathways and genomic regulation of antigen-specific PC precursors are not fully understood.

Purpose of the Study:

• To elucidate the developmental dynamics and genomic programs of antigen-specific plasma cell precursors.
• To investigate the biphasic generation of PC precursors during the germinal center response.
• To identify the factors influencing the generation of long-lived bone marrow PCs.

Main Methods:

• Utilized a model antigen system in mice.
• Employed single-cell RNA sequencing and B cell antigen receptor sequencing.
• Conducted clonal tracing and adoptive transfer experiments in spleen and bone marrow.

Main Results:

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

Conclusions:

• Proposed a model for the proliferation and programming of long-lived PC precursors.
• Highlighted the role of extended antigen encounters in the GC for precursor development.
• Revealed a new understanding of plasma cell differentiation and longevity.