Vaginal epithelial cells regulate membrane adhesiveness to co-ordinate bacterial adhesion

Area of Science:

• Microbiology
• Cell Biology
• Gynecology

Background:

• The vaginal microbiome's bacterial composition influences health and disease.
• Mechanisms of bacterial adhesion to vaginal epithelial cells are not fully understood.
• Regulation of bacterial adhesion by specific cell membrane regions is unknown.

Purpose of the Study:

• To investigate the role of epithelial cell membrane regions in bacterial adhesion.
• To determine if vaginal epithelial cells regulate bacterial adhesion spatially.
• To identify factors influencing bacterial adhesion forces on epithelial surfaces.

Main Methods:

• Atomic force microscopy to measure bacterial adhesion forces.
• Depletion of epithelial cell membrane cholesterol and cortical actin.
• Microscopy to quantify bacterial adherence to specific cell regions.

Main Results:

• Bacterial adhesion forces are significantly stronger on membrane regions away from the nucleus compared to regions above the nucleus.
• Adhesion force ratios correlate with the number of adhering bacteria across different membrane regions.
• Depleting epithelial cell membrane cholesterol or cortical actin drastically reduces bacterial adhesion.

Conclusions:

• Vaginal epithelial cells actively regulate bacterial adhesion by modulating specific membrane regions.
• The nucleus-proximal membrane region appears to discourage bacterial adhesion, potentially for nuclear protection.
• Cholesterol and cortical actin are critical for robust bacterial adhesion to vaginal epithelial cells.