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Updated: Jul 17, 2026
07:49
Creating and Applying a Reference to Facilitate the Discussion and Classification of Proteins in a Diverse Group
Published on: August 16, 2017
Structure-dependent functional properties of human defensin 5.
Erik de Leeuw1, Scott R Burks, Xiangqun Li
1Institute of Human Virology, University of Maryland Biotechnology Institute, 725 West Lombard Street, Baltimore, MD 21201, USA. deleeuw@umbi.umd.edu
FEBS Letters
|January 26, 2007
Summary
Human defensin 5 (HD-5), an antimicrobial peptide, protects the gut. Its structure affects activity against certain bacteria and triggers immune signaling, suggesting a role in intestinal inflammation.
Area of Science:
- Immunology
- Microbiology
- Gastroenterology
Background:
- Mucosal epithelia employ antimicrobial peptides as a key component of innate immunity against microbial threats.
- Human defensin 5 (HD-5) is a crucial antimicrobial peptide synthesized by Paneth cells in the ileum.
Purpose of the Study:
- To elucidate the functional characteristics of human defensin 5 (HD-5) concerning its molecular structure.
- To investigate the role of HD-5 in modulating the intestinal immune response.
Main Methods:
- Assessed the antimicrobial activity of HD-5 against Escherichia coli and Staphylococcus aureus in relation to its structure.
- Evaluated HD-5's interaction with intestinal epithelial cell membranes.
- Measured interleukin-8 (IL-8) secretion in response to HD-5, with and without tumor necrosis factor alpha.
Main Results:
- HD-5's antimicrobial efficacy against Escherichia coli was structure-independent.
- Unstructured HD-5 exhibited significantly diminished antimicrobial activity against Staphylococcus aureus.
- HD-5 induced concentration- and structure-dependent interleukin-8 (IL-8) secretion from intestinal epithelial cells.
- Tumor necrosis factor alpha synergistically enhanced HD-5-induced IL-8 release.
Conclusions:
- HD-5 possesses distinct structure-activity relationships for antimicrobial functions against different bacterial species.
- HD-5 interacts with intestinal epithelial cells, modulating chemokine secretion.
- HD-5 may function as a regulator of the intestinal inflammatory cascade.
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