Related Experiment Video
Updated: Aug 7, 2026

Analyzing Beneficial Effects of Nutritional Supplements on Intestinal Epithelial Barrier Functions During Experimental Colitis
Published on: January 5, 2017
Innate immunity and colonic inflammation: enhanced expression of epithelial alpha-defensins
J Wehkamp1, B Schwind, K R Herrlinger
1Department of Internal Medicine I, University of Lübeck, Germany.
Abstract:
Human alpha-defensins contribute to local intestinal host defense as part of innate immunity and may be of major relevance in microbial infection and chronic inflammatory bowel disease. The objective was to investigate human defensin 5 and 6 (HD-5, HD-6) mRNA expression by RT-PCR from colonic biopsies and peptide expression by immunohistochemistry from colonic resections under basal and inflammatory conditions. Both alpha-defensins were induced by proinflammatory cytokines in cell culture. HD-5 mRNA expression was enhanced in both idiopathic and nonidiopathic inflammatory states of the large bowel [32% of control vs 73% of unspecific colitis, 69% of Crohn's disease (CD) and 73% of ulcerative colitis (UC)], whereas HD-6 was specifically related to CD and UC (14% in controls vs 20% in unspecific coltis, 49% in CD and 42% in UC). Immunohistochemistry confirmed the presence of HD-5 in colonic epithelium. Antimicrobial peptides in the colon may be of importance in maintaining the mucosal barrier and controlling microbial invasion in inflammatory bowel diseases.
Related Concept Videos
Defense Mechanism Against Infection
In addition, many body organ systems have unique defenses against infection. The skin is an intact, multilayered surface preventing invasion by microorganisms unless impaired. Mucous membranes lining the mouth, nose, and eyelids are barriers...
Renewal of Intestinal Stem Cells
Role of Ephrin-Eph Signalling in Intestinal Stem Cell Renewal
Role Of Notch Signalling In Intestinal Stem Cell Renewal
Direct cell-to-cell contact is needed for the activation of Notch signaling. The signal is initiated when a notch ligand binds to a receptor on an adjacent cell, also...
Inflammatory Bowel Disease II: Ulcerative Colitis
Inflammatory Bowel Disease III: Crohn's Disease

