Format

Send to

Choose Destination
See comment in PubMed Commons below
Parasite Immunol. 2003 May;25(5):259-70.

Mucosal defences against Giardia.

Author information

1
Department of Medicine, University of California, San Diego, La Jolla, California 92093, USA. leckmann@ucsd.edu

Abstract

Giardia lamblia (syn. G. duodenalis or G. intestinalis), the causative agent of giardiasis, is one of the most common causes worldwide of intestinal infections in humans. Symptomatic infection is characterized by diarrhoea, epigastric pain, nausea, vomiting, and weight loss, yet many infections are asymptomatic. The protozoan, unicellular parasite resides in the lumen and attaches to the epithelium and overlying mucus layers but does not invade the mucosa and causes little or no mucosal inflammation. Giardiasis is normally transient, indicating the existence of effective host defences, although re-infections can occur, which may be related to differences in infecting parasites and/or incomplete immune protection. Mucosal defences against Giardia must act in the small intestinal lumen in the absence of induction by classical inflammatory mediators. Secretory IgA antibodies have a central role in anti-giardial defence. B cell-independent mechanisms also exist and can contribute to eradication of the parasite, although their identity and physiological importance are poorly understood currently. Possible candidates are nitric oxide, antimicrobial peptides such as Paneth cell alpha-defensins, and lactoferrin. Elucidation of the key anti-giardial effector mechanisms will be important for selecting the best adjuvants in the rational development of vaccination strategies against Giardia.

PMID:
12969444
[Indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Wiley
    Loading ...
    Support Center