Periodontal ligament stem cells regulate B lymphocyte function via programmed cell death protein 1.

Area of Science:

• Immunology
• Regenerative Medicine
• Stem Cell Biology

Background:

• Periodontal ligament stem cells (PDLSCs) are recognized for their role in tooth and periodontal tissue regeneration.
• PDLSCs can modulate T-cell immunity, but their effects on B cells are not well understood.

Purpose of the Study:

• To investigate the impact of allogeneic PDLSCs on humoral immunity in a periodontitis model.
• To elucidate the mechanisms by which PDLSCs influence B cell function.

Main Methods:

• Treatment of periodontitis in a miniature pig model with allogeneic PDLSCs.
• Co-culture of human PDLSCs (hPDLSCs) with normal B cells.
• Analysis of B cell proliferation, differentiation, migration, and viability.
• Investigation of cell-to-cell contact mechanisms involving PD-1 and PD-L1.

Main Results:

• Allogeneic PDLSC treatment reduced humoral immunity in periodontitis models.
• hPDLSCs suppressed B cell proliferation, differentiation, and migration, similar to bone marrow mesenchymal stem cells.
• hPDLSCs enhanced B cell viability via interleukin-6 secretion.
• hPDLSCs inhibited B cell activation through cell-to-cell contact, primarily mediated by programmed cell death protein 1 (PD-1) and programmed cell death 1 ligand 1 (PD-L1).

Conclusions:

• PDLSCs possess a previously unrecognized function in regulating humoral immune responses.
• PDLSCs modulate B cell activity through both suppressive and supportive mechanisms.
• PDLSCs may represent a novel therapeutic target for immune-related disorders.