Role of Processing and Intracellular Transport for Optimal Toxicity of Shiga Toxin and Toxin Mutants

Garred, Øystein; Dubinina, E. E.; Holm, Pernille; Olsnes, Sjur; Deurs, Bo van; Kozlov, J. V.; Sandvig, Kirsten

doi:10.1006/excr.1995.1128

Cited by 67 publications

(73 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…28,52 The A chain of VT-1 promotes cell death by inhibiting protein synthesis as a consequence of modifying ribosomal RNA. 16,17 While still requiring the B chain to gain entry into a target cell, it is questionable whether CD77-dependent pathways additional to those of simple binding and This statement is based on the observation that VT-1 holotoxin kills cells at concentrations considerably less (510 ng/ml) than those required for B chain to be active (410 mg/ml). The involvement of an apoptotic component to holotoxin-mediated death is not ruled out however.…”

Section: Discussionmentioning

confidence: 99%

“…Cleavage at this site is important for optimal activation of toxin during cellular uptake. 16 CD77 permits the cellular entry of VT-1 through an initial binding of the pentameric B subunits of the holotoxin. Subsequent endocytosis of toxin to the endoplasmic reticulum, and membrane translocation to the cytosol, results in the inactivation of ribosomes by the toxin's catalytic A1 subunit.…”

Section: Introductionmentioning

confidence: 99%

“…This inactivation involves a specific depurination of 28S ribosomal RNA which renders the ribosomes unable to function in protein synthesis: an event which ultimately leads to the death of the cell. 16,17 VT-1 has thereby been mooted as a potential delivery system for toxin-based therapy of CD77-expressing lymphoma: indeed, a range of BL cell lines have been shown to die on exposure to the holotoxin in culture. 9,18 In addition to the ribosome-inactivating properties of the A chain, it was found that B chain pentamer ± when present at sufficiently high concentration ± was, of itself, able to deliver a death signal to BL cells.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

CD40 ligand, Bcl-2, and Bcl-xL spare group I Burkitt lymphoma cells from CD77-directed killing via Verotoxin-1 B chain but fail to protect against the holotoxin

et al. 2000

View full text Add to dashboard Cite

Owing to its lineage and differentiation stage-restricted expression, CD77 has been mooted as a therapeutic target in Burkitt lymphoma (BL). The recognition that the globotriaosyl moiety of this neutral glycosphingolipid is a receptor for Escherichia coli-derived Verotoxin-1 (Shiga-Like Toxin-1) offers a potential delivery system for the attack. Here we show that CD77-expressing Group I BL cells which are normally susceptible to activation-induced death on binding Verotoxin-1 B chain are protected in the presence of CD40 ligand. Ectopic expression of either bcl-2 or bcl-x L also afforded resistance to the actions of the B chain. In total contrast, neither of the survival genes nor a CD40 signal ± even when acting in concert ± protected against killing mediated by the holotoxin. These findings indicate that while therapeutic modalities for CD77-expressing B cell tumors (which include follicular lymphoma) based on the use of Verotoxin-1 B chain might be compromised by the activation of endogenous or exogenous survival pathways, those exploiting the holotoxin should be left unscathed. Cell Death and Differentiation (2000) 7, 785 ± 794.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

CD40 ligand, Bcl-2, and Bcl-xL spare group I Burkitt lymphoma cells from CD77-directed killing via Verotoxin-1 B chain but fail to protect against the holotoxin

et al. 2000

View full text Add to dashboard Cite

show abstract

“…Previous studies have shown that the whole toxin as well as isolated B-fragment are transported from the plasma membrane to the ER of toxin sensitive cells (15)(16)(17)(18). To quantify this transport by monitoring the appearance of Shiga toxin B-fragment in the ER, an N-glycosylation site was added to the carboxyl terminus of the protein (Fig.…”

Section: Shiga Toxin B-fragment With An N-glycosylation Site and The mentioning

confidence: 99%

“…These toxins are composed of two polypeptidic chains, one of which (A-fragment) carries a deadenylase activity that inhibits protein biosynthesis by acting on the 28 S rRNA, whereas the other subunit (B-fragment) allows the binding of the toxin to target cells (14). Electron microscopic analysis has shown that Shiga toxin can be detected in the ER of T47D cells, of butyric acid-treated A431 cells, and of Daudi cells (15)(16)(17)(18). Shiga toxin does not carry a KDEL motif at its carboxyl terminus, and the mechanism of its retrograde transport is currently unknown.…”

mentioning

confidence: 99%

Retrograde Transport of KDEL-bearing B-fragment of Shiga Toxin

Johannes¹,

Tenza

Antony

et al. 1997

Journal of Biological Chemistry

187

254

View full text Add to dashboard Cite

To investigate retrograde transport along the biosynthetic/secretory pathway, we have constructed a recombinant Shiga toxin B-fragment carrying an N-glycosylation site and a KDEL retrieval motif at its carboxyl terminus (B-Glyc-KDEL). After incubation with HeLa cells, B-Glyc-KDEL was progressively glycosylated in the endoplasmic reticulum (ER) and remained stably associated with this compartment. B-fragment with a nonfunctional KDEL sequence (B-Glyc-KDELGL) was glycosylated with about the same kinetics as B-Glyc-KDEL but localized at steady state to the Golgi apparatus. Morphological studies showed that B-Glyc-KDEL was delivered from the plasma membrane, via endosomes and the cisternae of the Golgi apparatus, to the ER. Moreover, the addition of a sulfation site allowed us to show that B-Glyc-KDEL on transit to the ER entered the Golgi apparatus through the trans-Golgi network. Transport of B-Glyc-KDEL to the ER was slowed down by nocodazole, indicating that microtubules are important for the retrograde pathway. Our results document the existence of a continuous pathway from the plasma membrane to the endoplasmic reticulum via the Golgi apparatus and show that a fully folded exogenous protein arriving in the endoplasmic reticulum via this pathway can undergo N-glycosylation.

show abstract

Therapy and prophylaxis of inhaled biological toxins

Paddle¹

2003

J of Applied Toxicology

View full text Add to dashboard Cite

This review highlights the current lack of therapeutic and prophylactic treatments for use against inhaled biological toxins, especially those considered as potential biological warfare (BW) or terrorist threats. Although vaccine development remains a priority, the use of rapidly deployable adjunctive therapeutic or prophylactic drugs could be life-saving in severe cases of intoxication or where vaccination has not been possible or immunity not established. The current lack of such drugs is due to many factors. Thus, methods involving molecular modelling are limited by the extent to which the cellular receptor sites and mode of action and structure of a toxin need to be known. There is also our general lack of knowledge of what effect individual toxins will have when inhaled into the lungs - whether and to what extent the action will be cell specific and cytotoxic or rather an acute inflammatory response requiring the use of immunomodulators. Possible sources of specific high-affinity toxin antagonists being investigated include monoclonal antibodies, selected oligonucleotides (aptamers) and derivatized dendritic polymers (dendrimers). The initial selection of suitable agents of these kinds can be made using cytotoxicity assays involving cultured normal human lung cells and a range of suitable indicators. The possibility that a mixture of selected antibody, aptamer or dendrimer-based materials for one or more toxins could be delivered simultaneously as injections or as inhaled aerosol sprays should be investigated.

show abstract

Role of Processing and Intracellular Transport for Optimal Toxicity of Shiga Toxin and Toxin Mutants

Cited by 67 publications

References 0 publications

CD40 ligand, Bcl-2, and Bcl-xL spare group I Burkitt lymphoma cells from CD77-directed killing via Verotoxin-1 B chain but fail to protect against the holotoxin

CD40 ligand, Bcl-2, and Bcl-xL spare group I Burkitt lymphoma cells from CD77-directed killing via Verotoxin-1 B chain but fail to protect against the holotoxin

Retrograde Transport of KDEL-bearing B-fragment of Shiga Toxin

Therapy and prophylaxis of inhaled biological toxins

Contact Info

Product

Resources

About