Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Hebrew University research team discovers path to blocking fatal toxins

14.09.2011
A team of researchers at the Hebrew University of Jerusalem says it has found a way to block a group of fatal bacterial toxins that have to date resisted all attempts to arrest them through the use of conventional drugs.

These toxins, called superantigens, are produced by a group of "violent" staphylococcal and streptococcal bacteria. When these bacteria attack humans, they set off an extreme immune reaction described as an "immune storm," that is, an immune response of a magnitude higher in intensity than during a regular immune reaction. The result is often fatal toxic or septic shock brought on by the excessive immune response.

Working to develop the first effective antidote under funding from the Defense Advanced Research Projects Agency of the US Department of Defense and the US National Institutes of Health, the laboratory headed by Prof. Raymond Kaempfer of the Institute for Medical Research Israel Canada (IMRIC) at the Hebrew University Faculty of Medicine, has studied how superantigen toxins engage the immune system. The researchers discovered that in order to exert its harmful action, a superantigen must first bind to a protein on the surface of the human immune cell, a receptor called CD28.

CD28 has been known for a long time as a key participant in every immune response, but its ability to recognize microbial components -- the superantigens -- came as a complete surprise. The Kaempfer team discovered that superantigens do their lethal work by co-opting CD28 as their receptor, and that binding of a superantigen to CD28 is the key in the pathway to an immune storm.

They mapped the regions where the superantigen and CD28 contact each other and found that to induce an immune storm, superantigens must bind specifically into that part of the CD28 molecule where, normally, it pairs with another CD28 molecule.

Using that insight, they next designed decoys, short protein fragments that mimic the contact domain in the superantigen or in CD28. Such decoys, they could show, act as a monkey wrench that blocks the engagement of CD28 receptor by the superantigen toxin, thereby inhibiting the overly strong immune response and protecting animals from the toxic consequences, including from death.

All the superantigen toxins function via the same CD28 receptor, rendering the decoys broadly effective as protective agents. The decoys proved safe in healthy, normal, laboratory animals.

These findings provide a novel therapeutic approach against toxic shock. The decoys are host-oriented therapeutics, directed at the human immune system itself, rather than at the pathogen. Using a host-oriented therapeutic, resistance cannot arise in the infecting bacteria or in the toxins because the decoy targets a human immune receptor that is constant and will not change.

The work of Kaempfer and his team will be published in the PLoS Biology journal on Sept. 13. Reviewers who have seen an advanced copy have called the work "a surprising result with enormous implications" and "a paradigm shift in superantigen research."

The Kaempfer team involved senior researcher Dr. Gila Arad and graduate students Revital Levy, Iris Nasie, Ziv Rotfogel, Uri Barash, Emmanuelle Supper, Tomer Shpilka, and Adi Minis, with the support of lab technician Dalia Hillman.

Jerry Barach | Hebrew University of Jerusalem
Further information:
http://www.huji.ac.il

Further reports about: CD28 immune cell immune reaction immune response immune system

More articles from Life Sciences:

nachricht Topologische Quantenchemie
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

nachricht Topological Quantum Chemistry
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>