Single-cell analysis reveals a unique microenvironment in peri-implantitis.

Area of Science:

• Oral biology
• Immunology
• Genomics

Background:

• Peri-implantitis (PI) is a significant complication of dental implants.
• Understanding the unique microenvironment of PI is crucial for effective treatment.
• Comparison with periodontitis (PD) and healthy controls provides critical context.

Purpose of the Study:

• To elucidate the distinct cellular and molecular characteristics of the peri-implantitis microenvironment.
• To identify key cellular players and interactions driving PI pathogenesis.
• To differentiate the microenvironment of PI from periodontitis (PD).

Main Methods:

• Single-cell RNA sequencing (scRNA-seq) of biopsies from patients with PI, PD, and healthy individuals (H).
• Comparative analysis of cellular composition, including stromal and immune cells.
• Investigation of cell-cell communication pathways and ligand-receptor interactions.

Main Results:

• PI exhibits decreased stromal cells and increased immune cell infiltration compared to H and PD.
• A unique CXCL13+ fibroblast sub-cluster, not found in PD or H, is enriched in PI.
• CXCL13+ fibroblasts recruit neutrophils via CXCL8/CXCL6-CXCR2/CXCR1, and promote monocyte differentiation into osteoclasts, leading to bone resorption.

Conclusions:

• The study identifies a unique immune microenvironment in PI, distinct from PD.
• Specific fibroblast-immune cell interactions in PI contribute to severe bone loss.
• Findings offer potential targets for novel and specific PI treatments.