Researchers from the Hebrew University have for the first time found a way to stop deadly toxins

This is a new approach to developing drugs against lethal shock

A team of researchers from the Hebrew University found for the first time a way to block the activity of deadly toxins of the super antigen type that create an acute inflammatory reaction that can cause death and that until today were resistant to conventional drugs.

When violent bacteria such as staphylococcus or streptococcus attack the human body, the immune system reacts in an extreme and much stronger way than its normal reaction. As a result of the acute reaction known as "immune storm", an infectious shock (Septic Shock) or a toxic shock (Toxic Shock) is created, both of which can be fatal.

The team of researchers from the Israel-Canada Medical Research Institute in the Faculty of Medicine of the Hebrew University, led by Prof. Raymond Kempfer, funded by the Defense Advanced Research Projects Agency of the US Department of Defense (DARPA) and the US National Institutes of Health (NIH), studied how the deadly toxins Create a response in the immune system. The researchers were surprised to discover that a protein known as 28CD, which is located on the wall of white immune cells in the human body and plays an important role in every response of the immune system, can recognize toxins and bind to them. It is this attachment that causes the lethal effect of the toxin on the human body and is the key step in its activity.

The researchers mapped the areas of contact between the toxin and the CD28 protein and found that in order to create an "immune storm" the toxin must stick specifically to that area of ​​the protein that is usually intended for another protein of the same type. In the next step, the researchers created "baits" - short sections of protein that mimic the contact areas. The baits act as a wrench and disrupt the binding of the toxin to the CD28 protein, inhibiting the strong immune response. By "blocking" the connection between the toxin and the protein, the baits are protected from the dangerous consequences of the toxin. The baits were found to be effective on a large scale since the toxins always bind to the same target protein CD28.

According to Prof. Kaempfer, "The discovery that CD28 binds to toxins makes it possible to use a new approach to the development of drugs against lethal shock, since these drugs are directed against the person himself and not against the invading agent. Therefore, bacteria and toxins cannot develop resistance against such drugs."

The important research was conducted as part of the development of protective measures against toxins that could be used as biological weapons. Reviewers who saw an early copy of the study that is about to be published in the respected journal PLoS Biology said that it was a "surprising result with huge implications" and a "total revolution in the field of super antigens".

Prof. Kempfer's team includes the senior researcher Dr. Gila Arad and the doctoral and graduate students Roital Levy, Iris Nashi, Ziv Rothfogel, Uri Barash, Emmanuela Sofer, Tomer Spilka and Adi Minnis, in collaboration with research worker Dalia Hillman.