Novel Assay To Characterize Neutrophil Responses to Oral Biofilms

Area of Science:

• Immunology
• Oral Biology
• Microbiology

Background:

• Neutrophils are key immune cells in oral health, interacting with microbial biofilms.
• Dysregulated neutrophil function contributes to periodontal disease pathogenesis.
• Existing assays often use planktonic bacteria, limiting understanding of biofilm interactions.

Purpose of the Study:

• To develop and validate an in vitro assay for assessing neutrophil activation by oral monospecies bacterial biofilms.
• To characterize species-specific neutrophil responses to commensal and pathogenic oral bacteria.
• To correlate neutrophil activation marker expression with functional outcomes.

Main Methods:

• Development of a flow cytometry-based assay measuring CD marker expression on neutrophils.
• Exposure of neutrophils to monospecies biofilms of prominent oral commensal and pathogenic bacteria.
• Performance of functional assays: phagocytosis, reactive oxygen species production, Nrf2 activation, NET formation, and myeloperoxidase release.

Main Results:

• Neutrophils exhibit distinct activation patterns in response to different oral bacterial species.
• The assay successfully characterized species-specific changes in neutrophil CD marker expression.
• Functional assays provided correlations between CD marker expression and neutrophil activity.

Conclusions:

• The developed assay provides a robust method for studying neutrophil-biofilm interactions in vitro.
• Neutrophil responses are highly specific to the encountered bacterial species.
• This assay can elucidate neutrophils' role in oral health and periodontal disease.