Defensins and cathelicidins in gastrointestinal infections : Current Opinion in Gastroenterology (original) (raw)
Gastrointestinal infections
aRobert Bosch Hospital, Stuttgart, Germany
bDr Margarethe Fischer Bosch Institute of Clinical Pharmacology, Stuttgart, Germany
cDivision of Dermatology, Department of Medicine, University of California San Diego and VA San Diego Healthcare Center, San Diego, USA
Correspondence to Jan Wehkamp, MD, Dr Margarethe Fischer-Bosch – Institute of Clinical Pharmacology, Auerbachstr. 112, 70376 Stuttgart, Germany Tel: +49 711 8101 3753; fax: +49 711 85 92 95; e-mail: [email protected]
Abstract
Purpose of review
To review recently published studies presenting novel and relevant information on antimicrobial peptides in gastrointestinal infections.
Recent findings
Defensins and cathelicidins are important antimicrobial peptides expressed by the gastrointestinal epithelium. Their localization and regulation have been the focus of current research establishing the relevance of these peptides both in counteracting an attack by pathogens as well as in controlling the endogenous bacterial flora. In the small intestine, Paneth cell α-defensins maintain a low level of microorganisms and regulate the composition of the bacterial flora. In contrast, a constitutive β-defensin can be found in nearly all gastrointestinal tissues. Other relevant β-defensins as well as human cathelicidin are inducible by inflammation or infections. Thus Helicobacter pylori enhances defensin expression in the gastric mucosa and Campylobacter jejuni and Salmonella provoke a similar response in the colon. Other pathogenic bacteria may suppress the antimicrobial peptide response as an escape strategy. Notably, the therapeutic induction of cathelicidins alleviates experimental shigellosis, suggesting a future role of endogenous antibiotics in medical therapy.
Summary
These recent findings together with a better understanding of underlying mechanisms involved in the regulation and biology of antimicrobial peptides will open up new therapeutic avenues to battle infections.
© 2007 Lippincott Williams & Wilkins, Inc.