anthrax lethal factor Archives

Anthrax toxin can enter living cells and the toxin enzymes, Lethal Factor (LF), and Edema Factor (EF) make known changes. Because of this activity, anthrax toxins are valuable tools to investigate cell processes. Some of the work currently accomplished with these toxins can be described by the following selected references:

Work with anthrax toxins is providing a better understanding of cellular processes. Protectative Antigen (PA) binds specifically to two toxin receptors, tumor endothelial marker 8 (TEM8, also called ANTXR1) and capillary morphogenesis 2 (CMG2, or ANTXR2). Several other factors are involved in the internalization of anthrax toxin.

Abrami L, Bischofberger M, Kunz B, Groux R, van der Goot FG (2010) Endocytosis of the Anthrax Toxin Is Mediated by Clathrin, Actin and Unconventional Adaptors. PLoS Pathog 6(3): e1000792. PMID: 20221438

Anthrax vaccines are currently under development and demonstration that antibodies will neutralize anthrax toxin is essential.

Laws TR, Kuchuloria T, Chitadze N, et al (2016) A Comparison of the Adaptive Immune Response between Recovered Anthrax Patients and Individuals Receiving Three Different Anthrax Vaccines. PLoS One 11(3):e0148713. Published 2016 Mar 23. doi:10.1371/journal.pone.0148713 PMID: 27007118

PA could potentially deliver polypeptides and compounds to the cell cytoplasm. In the two studies described in the following papers, PA was used as a tool to deliver biochemicals to the cytoplasm of eukaryotic cells.

Dyer PDR, Shepherd TR, Gollings AS et al (2015) Disarmed anthrax toxin delivers antisense oligonucleotides and siRNA with high efficiency and low toxicity. J. Control. Release 2015, 220, 316–328. PMID: 26546271

Rabideau, AE, Liao XL, Akcay G, Pentelute BL (2015) Translocation of Non-Canonical Polypeptides into Cells Using Protective Antigen. Sci Rep 5: 11944, PMID:26178180, PMCID: PMC 4503955

PA has been used to target cancer cells overexpressing TEM8. This receptor has been shown to be upregulated during tumor angiogenesis and provides a convenient target for anti-angiogenic therapy.

Chen KH, Liu S, Bankston LA, Liddington RC, Leppla SH (2007) Selection of anthrax toxin protective antigen variants that discriminate between the cellular receptors TEM8 and CMG2 and achieve targeting of tumor cells. J Biol Chem 282: 9834–9845. PMID: 17251181, PMCID: PMC2530824

Chaudhary A, Hilton MB, Seaman S, et al (2012) TEM8/ANTXR1 blockade inhibits pathological angiogenesis and potentiates tumoricidal responses against multiple cancer types. Cancer Cell 21:212–226. PMID: 22340594 PMCID: PMC3289547

To learn more about how our highly purified Anthrax Toxins were used in research, check out our over 200 Anthrax Toxin citations.

A fast, sensitive, specific and accurate detection method to determine active infection

Dr. Nancy Shine
(408) 874-1305
NShine@ListLabs.com

[Campbell, CA, 11/29/2018]

• Method to detect Anthrax before it’s deadly
• Anthrax is a problem for livestock
• Test method is both specific and sensitive for Anthrax
• List Labs is looking to partner on this newly discovered method

Since the intentional release of anthrax spores leading to lethal inhalational
anthrax in 2001, the need for rapid and sensitive detection of infection has been critical.
Unfortunately, early symptoms of infection are similar to those of common illnesses.
While the symptoms are not remarkable, the Bacillus anthracis bacteria enter the
patient’s blood stream and rapidly multiply. This expanding population of bacteria
produces deadly proteins which will eventually overcome the patient. Classical
techniques to detect and identify bacteria in blood take too long. We have devised a
rapid method for detecting one of the proteins produced in the infection. This protein,
anthrax lethal factor, is produced early in infection in a quantity sufficient for detection
making it possible to rapidly determine that a patient is infected and to initiate therapy. A
quick diagnosis is essential for successful treatment of the disease.

Anthrax is not only a bioterrorism threat. There are many areas in the world
where anthrax is endemic. Efforts have been focused on surveillance in countries where
livestock are infected. Contact between infected animals and humans leads to disease.
A quick diagnosis depends on the availability of a rapid, sensitive and simple test.

This paper reports the design of a sensitive and specific test for anthrax infection.
A reagent that specifically detects the presence of low amounts of lethal factor from
anthrax infection is described. This study sets a new standard for a sensitive, simple,
and specific method to detect anthrax infection.

List Labs is looking to partner with an organization that can take this biotechnology to the level of application in the field. Please contact Dr. Shine if you’re interested in partnering.

About List Biological Labs, Inc.

Established since 1978, List Biological Labs, Inc. specializes in native toxins, recombinant proteins, bacteria, Biotherapeutics and GMP products. We develop assays, perform contract manufacturing and produce our own GMP LPS product.

List Labs produces toxins for the research community, including: C. difficile toxin A and toxin B, shiga toxins, cholera toxin, anthrax toxins (PA, LF, and EF), pertussis toxin, diphtheria toxin, CRM197, tetanus toxin, staphylococcal enterotoxin B, botulinum toxins as well as several types of lipopolysaccharides (LPS) or endotoxin for purchase by the research community.

By: Nancy Shine, PhD, Director of R&D, List Labs

Nancy Shine presenting her poster at ASM Biothreats February, 2018

A fast, sensitive, specific and accurate detection method to determine active infection by Bacillus anthracis in plasma has been developed at List Biological Laboratories.

Bacillus anthracis is regarded as a major biological warfare threat. The inhalation form of Bacillus anthracis infection can kill quickly. While antibiotic treatment can clear the bacterium from the host, if diagnosis is delayed, the toxin, which is rapidly produced, may already be present in lethal amounts. There is a critical need for a rapid, accurate, sensitive and simple assay to determine whether infection has occurred thereby allowing immediate treatment.

Anthrax Detection Method

Anthrax lethal factor (LF), an endopeptidase, is present in blood in the early stages of the infection. The use of peptidic substrates in plasma is problematic due to the presence of other proteases and the likelihood of nonspecific cleavage of the substrate. A fluorescently labeled peptide substrate, MAPKKide Plus, Prod #532, which is not cleaved by plasma proteases and thus is specific for LF has been designed. The LF is enriched by capture from plasma using an LF antibody-coated microtiter plate, and the captured LF is then exposed to the fluorescent substrate. The amount of cleaved peptide substrate is determined by HPLC with fluorescence detection. Concentration of the LF using the antibody-coated plates allows for the detection of 5 pg LF/ml of neat plasma after 2 hours of incubation. Alternately, the MAPKKide Plus may be added directly to diluted plasma and cleavage monitored by an increase in fluorescence as a function of time using a fluorescent microplate reader. The limit of detection by this simpler method is 1 ng LF/ml of plasma after 5 hours of digestion. Both methods can be confirmed by analysis of the reaction as a function of time. These methods are described in the poster Sensitive Detection of Anthrax Lethal Factor in Plasma Using a Specific Biotinylated Fluorogenic Substrate.

What’s Next for Anthrax Detection Method

We are currently working with a biotinylated form of MAPKKide Plus to enhance the sensitivity of the simpler method using the fluorescent plate reader rather than HPLC.

You can see the poster here. To see a complete list of all of List Labs’ posters check out this blog post.

Interested in learning more about this List Labs patented peptide substrate? Contact us!

By: Rachel Berlin, Marketing Manager

List Labs is proud to be exhibiting at ASM Biothreats February 12-14th. The conference will be held in Baltimore, Maryland at the Hilton Hotel.

Thought leaders in academia, industry and government will gather to present and discuss the latest developments in the emerging field of biothreats. This year’s conference has an expanded program to include tracks on high consequence pathogen research, biological threat reduction, product development, and policy.

List Labs will be exhibiting in booth #29 and Nancy Shine will be presenting her poster on Sensitive Detection of Anthrax Lethal Factor in Plasma Using a Specific Biotinylated Fluorogenic Substrate during poster session 1 on Wednesday, February 14th from 10:30 AM- 11:30 AM in space #020. Come learn about our products that assist in the biological threat reduction such Botulinum Neurotoxins, Anthrax Lethal Factor, FRET Peptides, Shiga Toxins, Tetanus Toxins, and more! All of our research reagents are available for purchase on our website.

Visit Nancy and Karen in the List Labs booth #29, or contact us to schedule a time to meet with them at the show. Click here for more information or to register for this conference.

Nancy Shine, PhD, Director R&D, List Labs and author of posters

Over 20 Scientific Posters Available on our website

Scientific posters are a great way to visually display complex scientific issues. List Labs has a large list of scientific posters published on our website under the specific products they pertain to. We have been getting a lot of requests lately to compile a list of all of our published posters into one place. Please see below for a comprehensive list of all List Labs’ scientific posters to date.

Click on the one you are interested in to check it out.

Cholera Toxins

HPLC Method to Assay the ADP-Ribosyltransferase Activity of Cholera Toxin

Botulinum Toxins

Anthrax Toxins