Related Experiment Video
Updated: Aug 17, 2026
11:15
In Situ Detection of Bacteria within Paraffin-embedded Tissues Using a Digoxin-labeled DNA Probe Targeting 16S rRNA
Published on: May 21, 2015
Localized antimicrobial peptide expression in human gingiva
B A Dale1, J R Kimball, S Krisanaprakornkit
1Department of Oral Biology, School of Dentistry, University of Washington, Seattle 98195-7132, USA. bdale@u.washington.edu
Journal of Periodontal Research
|October 5, 2001
Summary
Oral epithelia utilize distinct antimicrobial peptides for defense. Beta-defensins are found in stratified epithelia, while alpha-defensins and LL-37 are in neutrophils within the junctional epithelium, suggesting site-specific roles.
Area of Science:
- Oral biology
- Immunology
- Microbiology
Background:
- Oral epithelia face constant bacterial challenge, relying on innate immunity and neutrophil recruitment.
- Antimicrobial peptides (AMPs) from epithelial cells and phagocytes form a crucial defense barrier.
Purpose of the Study:
- To investigate the localization and expression of AMPs, specifically beta-defensins, alpha-defensins, and cathelicidin LL-37, within the different epithelial tissues of the periodontium.
- To understand the cellular sources and regulation of these AMPs in response to the oral environment.
Main Methods:
- Utilized antibodies and in situ hybridization to detect AMPs and their mRNA in gingival tissue sections.
- Examined AMP expression in cultured gingival epithelial cells under various conditions, including differentiation and stimulation.
Main Results:
- Beta-defensins (hBD-1, hBD-2) were localized in suprabasal layers of stratified gingival epithelia and expressed by differentiating epithelial cells.
- hBD-2 expression in epithelial cells required stimulation by inflammatory mediators or bacterial products.
- Beta-defensins were absent in the junctional epithelium (JE).
- Alpha-defensins and LL-37 were detected in neutrophils migrating through the JE, with increased presence during inflammation.
- JE contained exogenously expressed alpha-defensins and LL-37, whereas stratified epithelium showed endogenous beta-defensin expression.
Conclusions:
- Antimicrobial peptides are differentially localized and expressed in distinct cell types within the periodontium.
- Beta-defensins are primarily associated with stratified epithelia, while alpha-defensins and LL-37 are linked to neutrophils in the JE.
- These findings suggest specialized roles for different AMPs in defending specific regions of the gingiva against bacterial challenge.
Related Concept Videos
01:27The Oral Microbiota
The oral microbiome includes a complex ecosystem comprising over 700 microbial species, identified through genomic sequencing and culture-based analyses to date. This community includes a core microbiome, found universally among individuals, and a variable component influenced by environmental factors such as diet, lifestyle, and host genetics. Site-specific conditions, including oxygen gradients, pH levels, and nutrient availability, determine the spatial distribution of these microorganisms...
01:29Microbiota of the Respiratory Tract
The human respiratory tract, comprising the upper and lower segments, serves as a critical interface with the external environment. The upper respiratory tract (URT)—including the nostrils, sinuses, pharynx, and oropharynx—is heavily colonized by microbes, while the lower respiratory tract (LRT), composed of the larynx, trachea, bronchi, and lungs, was long thought to be sterile. However, recent molecular studies have revealed that the lungs are not devoid of microbes but act more like...