Single-cell RNA-seq reveals a resolving immune phenotype in the oral mucosa

Area of Science:

• Oral immunology
• Mucosal immunity
• Periodontal disease research

Background:

• The oral mucosa interfaces host immunity and oral microbiota.
• Periodontal disease involves a destructive immune response to microbial plaque.
• Resolving inflammation requires removing the microbial stimulus.

Purpose of the Study:

• To characterize the immune response in oral mucosa during periodontal health, disease, and resolution using single-cell RNA-sequencing.
• To identify key immune cells and gene expression patterns associated with disease resolution.
• To discover novel macrophage phenotypes involved in mucosal immune resolution.

Main Methods:

• Single-cell RNA-sequencing (scRNA-seq) of mouse oral mucosa.
• Analysis of gene expression across health, disease, and resolution states.
• Flow cytometry validation of identified macrophage subgroups.

Main Results:

• Gene expression shifts in macrophages and neutrophils drive immune responses across conditions.
• A unique gene signature characterizes the resolution of periodontal disease.
• A specific macrophage subgroup expands during resolution, exhibiting an immunoregulatory gene signature and expressing Cd74.
• Expansion of this resolution-associated macrophage subgroup was validated by flow cytometry.

Conclusions:

• Single-cell RNA-sequencing provides a robust dataset of oral mucosal immunological changes.
• Macrophages and neutrophils are key players in the immune response to periodontal disease and its resolution.
• A distinct immunoregulatory macrophage phenotype is identified and associated with the resolution of mucosal inflammation.