Researchers in Brazil have engineered a new protein from the toxin of a reaper spider that could herald a new generation of anti-venom vaccines. Serums or vaccines developed from the engineered protein could save thousands of lives worldwide and allow patients to receive treatment without having to suffer harmful side-effects, says the team from the Universidade Federal de Minas Gerais, whose study was published online in the journal Vaccine this week.

Reaper spiders, also known as brown spiders, comprise around 100 species of venomous spider belonging to the genus Loxosceles. They are found all over the world and produce very harmful venoms.

A bite from one of these spiders, which are most prevalent in Brazil, causes the skin surrounding the wound to die, and potentially more serious effects like kidney failure and hemorrhaging.

Corresponding author Carlos Chávez-Olortegui, says in a statement:

“In Brazil we see thousands of cases of people being bitten by Loxosceles spiders, and the bites can have very serious side- effects.”

“Existing anti-venoms are made of the pure toxins and can be harmful to people who take them. We wanted to develop a new way of protecting people from the effects of these spider bites, without having to suffer from side-effects,” he explains.

In their study, Chávez-Olortegui and colleagues describe how they took three pieces of a venom toxin from the Loxosceles intermedia spider and engineered a protein that is not itself toxic, but when tested on lab animals produced a reaction that protected them from the effects of the pure spider venom.

The team tested their new protein on rabbits. All the animals tested showed an immune response that was similar to that produced when injected with the whole toxin. They were protected from skin damage at the site of the injection and from hemorrhaging, say the researchers.

The engineered protein protected the rabbits against the venom of two species of Loxosceles, the intermedia and the gaucho, which have similar toxins.

The study shows it is possible to engineer an anti-venom protein that can protect against more than one toxin at a time, without the need for the venomous animal itself.

“It’s not easy taking venom from a spider, a snake or any other kind of venomous animal,” says Chávez-Olortegui, explaining that with their new approach, they could engineer the proteins in the lab, without having to extract whole toxins from the venom.

Current approaches to protecting people against poisonous spiders, snakes and other animals, make a serum from the antibodies that lab animals produce when they are injected with the venom. The problem with this method is you need to extract the crude venom from the venomous animal, and then the animals that are given the venom suffer from the toxin’s effects.

With the engineered protein approach, the protein is made repeatedly in the lab without the need for the venomous animal, and it does not harm the animals used to make the antibodies.

“This makes the whole process much safer,” says Chávez-Olortegui.

In their paper, he and his colleagues also conclude that “this engineered protein may be a promising candidate for therapeutic serum development or vaccination in the future”.

In April 2013, in a paper published online in Nature Nanotechnology, scientists in the US described how they developed tiny sponges made from nanoparticles disguised as red blood cells that can soak up a broad range of dangerous toxins in the blood, including snake and bee venom.

Written by Catharine Paddock PhD