Lectin-based food poisoning: a new mechanism of protein toxicity.
MetadataShow full item record
AbstractBACKGROUND: Ingestion of the lectins present in certain improperly cooked vegetables can result in acute GI tract distress, but the mechanism of toxicity is unknown. In vivo, gut epithelial cells are constantly exposed to mechanical and other stresses and consequently individual cells frequently experience plasma membrane disruptions. Repair of these cell surface disruptions allows the wounded cell to survive: failure results in necrotic cell death. Plasma membrane repair is mediated, in part, by an exocytotic event that adds a patch of internal membrane to the defect site. Lectins are known to inhibit exocytosis. We therefore tested the novel hypothesis that lectin toxicity is due to an inhibitory effect on plasma membrane repair. METHODS AND FINDINGS: Repair of plasma membrane disruptions and exocytosis of mucus was assessed after treatment of cultured cell models and excised segments of the GI tract with lectins. Plasma membrane disruptions were produced by focal irradiation of individual cells, using a microscope-based laser, or by mechanical abrasion of multiple cells, using a syringe needle. Repair was then assessed by monitoring the cytosolic penetration of dyes incapable of crossing the intact plasma membrane. We found that cell surface-bound lectins potently inhibited plasma membrane repair, and the exocytosis of mucus that normally accompanies the repair response. CONCLUSIONS: Lectins potently inhibit plasma membrane repair, and hence are toxic to wounded cells. This represents a novel form of protein-based toxicity, one that, we propose, is the basis of plant lectin food poisoning.
CitationPLoS ONE. 2007 Aug 1; 2(8):e687
- Disruption-induced mucus secretion: repair and protection.
- Authors: Miyake K, Tanaka T, McNeil PL
- Issue date: 2006 Sep
- Differential in vitro inhibitory activity against HIV-1 of alpha-(1-3)- and alpha-(1-6)-D-mannose specific plant lectins: implication for microbicide development.
- Authors: Saïdi H, Nasreddine N, Jenabian MA, Lecerf M, Schols D, Krief C, Balzarini J, Bélec L
- Issue date: 2007 Jun 12
- Mechanisms of mucus release in exposed canine gastric mucosa.
- Authors: Zalewsky CA, Moody FG
- Issue date: 1979 Oct
- Relationships between degree of binding, cytotoxicity and cytoagglutinating activity of plant-derived agglutinins in normal lymphocytes and cultured leukemic cell lines.
- Authors: Ohba H, Bakalova R
- Issue date: 2003 Jun
- Repair of the injury to respiratory epithelial cells characteristic of asthma is stimulated by Allomyrina dichotoma agglutinin specific serum glycoproteins.
- Authors: Patchell BJ, Dorscheid DR
- Issue date: 2006 May