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Updated: May 22, 2026
Inducing Apical Periodontitis in Mice
Published on: August 6, 2019
MxA expression induced by α-defensin in healthy human periodontal tissue
Rangsini Mahanonda1, Noppadol Sa-Ard-Iam, Pimprapa Rerkyen
1Department of Periodontology, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand. rangsini.m@chula.ac.th
Abstract:
Although periodontal tissue is continually challenged by microbial plaque, it is generally maintained in a healthy state. To understand the basis for this, we investigated innate antiviral immunity in human periodontal tissue. The expression of mRNA encoding different antiviral proteins, myxovirus resistance A (MxA), protein kinase R (PKR), oligoadenylate synthetase (OAS), and secretory leukocyte protease inhibitor (SLPI) were detected in both healthy tissue and that with periodontitis. Immunostaining data consistently showed higher MxA protein expression in the epithelial layer of healthy gingiva as compared with tissue with periodontitis. Human MxA is thought to be induced by type I and III interferons (IFNs) but neither cytokine type was detected in healthy periodontal tissues. Treatment in vitro of primary human gingival epithelial cells (HGECs) with α-defensins, but not with the antimicrobial peptides β-defensins or LL-37, led to MxA protein expression. α-defensin was also detected in healthy periodontal tissue. In addition, MxA in α-defensin-treated HGECs was associated with protection against avian influenza H5N1 infection and silencing of the MxA gene using MxA-targeted-siRNA abolished this antiviral activity. To our knowledge, this is the first study to uncover a novel pathway of human MxA induction, which is initiated by an endogenous antimicrobial peptide, namely α-defensin. This pathway may play an important role in the first line of antiviral defense in periodontal tissue.
Insights
Healthy gums possess innate antiviral defenses. Researchers discovered that alpha-defensins trigger myxovirus resistance A (MxA) protein expression, enhancing protection against viral infections in periodontal tissue.
Area of Science:
- Oral biology
- Immunology
- Virology
Background:
- Periodontal tissue faces constant microbial challenges but usually remains healthy.
- Innate antiviral immunity is crucial for maintaining oral tissue homeostasis.
- Understanding the mechanisms of antiviral defense in the periodontium is essential.
Purpose of the Study:
- To investigate innate antiviral immunity in human periodontal tissue.
- To identify key antiviral proteins and their regulation in gingival health and disease.
- To uncover novel pathways for antiviral defense in the periodontium.
Main Methods:
- Detection of antiviral protein mRNA (MxA, PKR, OAS, SLPI) in healthy and periodontitis tissues.
- Immunostaining for MxA protein expression in gingival tissue.
- In vitro treatment of human gingival epithelial cells (HGECs) with antimicrobial peptides.
- Assessment of MxA-induced antiviral activity against avian influenza H5N1.
- Gene silencing of MxA using siRNA.
Main Results:
- Antiviral protein mRNA detected in both healthy and periodontitis tissues.
- Higher MxA protein expression observed in the epithelial layer of healthy gingiva.
- Alpha-defensins, but not beta-defensins or LL-37, induced MxA expression in HGECs.
- Alpha-defensin and MxA were detected in healthy periodontal tissue.
- MxA induction by alpha-defensins conferred protection against H5N1 infection, which was abolished by MxA gene silencing.
Conclusions:
- A novel pathway for MxA induction in human periodontal tissue, initiated by alpha-defensins, has been identified.
- This alpha-defensin-MxA pathway represents a potential first line of innate antiviral defense in the periodontium.
- Understanding this pathway could lead to new strategies for managing viral infections in the oral cavity.
