Ricin, a plant-derived exotoxin, inhibits protein synthesis by ribosomal inactivation. Due to its wide availability and ease of preparation, ricin is considered a biothreat, foremost by respiratory exposure. We examined the in vivo interactions between ricin and cells of the lungs in mice intranasally exposed to the toxin and revealed multi-phasic cell-type-dependent binding profiles. While mac...

Vibrio vulnificus secrets a pore-forming toxin called Vibrio vulnificus hemolysin (VVH). In this study, we showed that methyl-beta-cyclodextrin (MβCD), an oligosaccharide, decreased binding of VVH to Chinese hamster ovary (CHO) cells, resulting in inhibition of its cytotoxicity. When the VVH was incubated with MβCD, cytotoxicity of the toxin was inhibited from 100.3 ± 7.2% to 19.6 ± 5.3%. Bindi...

Tetanus is a disease caused by tetanus toxin, a potent inhibitor for the release of inhibitory neurotransmitter in the central nervous system that causes spastic paralysis. Fragment C (52 kD) of this toxin is responsible for binding to the neuronal membrane. For this reason, and also its non toxigenic and immunogenic nature, this fragment might be ideal for new vaccine development. Presently, w...

Hemorrhage is a prominent clinical manifestation of systemic anthrax. Therefore, we have examined the effects of anthrax lethal and edema toxins on human platelets. We find that anthrax lethal toxin fails to cleave its target, mitogen-activated protein kinase 1, and anthrax edema toxin fails to increase intracellular cyclic adenosine monophosphate. Surface expression of toxin receptors tumor en...

We have tested the in vitro binding of Clostridium difficile toxin A (enterotoxin) and cholera toxin to intestinal brush border membranes prepared from either conventional or axenic mice. Membranes from axenic mice were shown to be saturated at a lower toxin A concentration (at least 2.5 times lower). Because there were no significant differences between membranes from axenic and conventional m...

objectives: enterotoxigenic escherichia coli (etec) is one of the most common agents of diarrhea among other bacterial agents. designing and producing vaccine against these bacteria is one of the major purposes of world health organization (who). due to presence of diverse clones of etec strains in the world, the use of global vaccines for etec infection is controversial. b subunit of heat labi...

Hemolytic-uremic syndrome is a clinical syndrome characterized by acute renal failure, microangiopathic hemolytic anemia, and thrombocytopenia that often follows infection by Shiga toxin- or verotoxin-producing strains of Escherichia coli. Because thrombocytopenia and platelet activation are hallmark features of hemolytic-uremic syndrome, we examined the ability of Shiga toxin to bind platelets...

Shiga toxin recognizes a galactose-alpha 1-->4-galactose terminal glycolipid, globotriaosylceramide (Gb3), in sensitive mammalian cells and is translocated by endocytosis to the cytoplasm, where it blocks protein synthesis. To determine if Gb3 is both required and sufficient for toxicity, Gb3 content in cells was altered by blocking key biosynthetic or degradative path enzymes with specific inh...

Insect midgut membrane-anchored aminopeptidases N (APNs) are Zn(++) dependent metalloproteases. Their primary role in dietary protein digestion and also as receptors in Cry toxin-induced pathogenesis is well documented. APN expression in few non-gut hemocoelic tissues of lepidopteran insects has also been reported but their functions are widely unknown. In the present study, we observed specifi...