Although modern methods of treating poisoning from snake venoms are quite developed, it is necessary to first identify the type of snake that bit a person in order to select the right antidote. But thanks to new research from an international team of scientists, this soon won't have to be the case. They have developed a universal antibody that neutralizes the deadly venom of cobras, kraits and mambas and has the potential to save tens of thousands of lives every year.

Poisoning due to snakebites is recognized as a serious global public health problem. According to various estimates (however, most of them are somewhat exaggerated), up to 138 thousand people die annually from snake bites, and more than 400 thousand remain disabled. It is mainly the populations of Africa and Asia that suffer, not only due to the high number of snakebite cases, but also due to limited access to adequate medical care.

Improved treatments are urgently needed to address this problem. Today, to combat poisoning from deadly snake venoms, it is necessary to accurately identify the type of snake that bit a person in order to select a suitable antidote. However, even in this case, complications in the form of serum sickness and anaphylaxis are not excluded – an allergic reaction of the body to the presence of a foreign antidote protein in the blood, which is often of animal origin.

Therefore, an international group of researchers from the USA, Great Britain and India decided to create a universal antidote against the deadly venom of snakes of the Elapidae family (asps). This extensive family includes 384 species of venomous snakes, including the most dangerous: king cobra, black mamba and Indian krait. Scientists reported on their development in an article published in the journal Science Translational Medicine.

First, the researchers isolated and compared the venom proteins of various adders. They found that a type of protein called three-fingered toxin (3FTx) is present in all slate snakes and contains small regions that are similar across species. In addition, 3FTx proteins are considered highly toxic and cause paralysis throughout the body, making them an ideal therapeutic target.

To find an antibody that blocks 3FTx and is least likely to cause an allergic reaction, biologists looked at a library containing more than 50 billion different human antibodies. They tested which ones bind best to different variants of the 3FTx protein. Thus, it was possible to narrow the search area to 30 antibodies, of which only one stood out for its strongest interaction with the venom toxin – antibody 95Mat5.

The scientists then tested the effects of the fully synthetic 95Mat5 on mice injected with toxins from the South China multibanded krait, monocled cobra, black mamba and king cobra. In all cases, rodents that were simultaneously injected with 95Mat5 were protected not only from death, but also from paralysis and any other complications. When the researchers looked at why 95Mat5 was so effective at blocking various variants of 3FTx, they found that the antibody mimicked the structure of the human protein that 3FTx normally binds to, causing muscle paralysis.

Although 95Mat5 is effective against the venom of all adders, it does not block the venom of vipers, the second large family of venomous snakes. In the future, the authors of the work plan to find broadly neutralizing antibodies against another toxin of adders, as well as two toxins contained in the venom of vipers. According to the researchers, combining 95Mat5 with three other antibodies could potentially work as a universal antivenin against any snake in the world.


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