New engineered spider protein could be the start of a new
generation of anti-venom vaccines, potentially saving thousands of lives
worldwide. The new protein, created from parts of a toxin from the reaper
spider, is described in the Elsevier journal Vaccine.
The researchers behind the study, from the Universidade
Federal de Minas Gerais in Brazil, say that the engineered protein may be a
promising candidate for developing therapeutic serums or vaccines against other
Reaper spiders, or brown spiders, are a family of species
found all over the world that produce harmful venoms. The toxic bite of these
spiders causes skin around the bite to die, and can lead to more serious
effects like kidney failure and haemorrhaging. These Loxosceles spiders are
most prevalent in Brazil, where they cause almost 7 000 human accidents every
How it works
The new study describes an engineered protein made of three
pieces of a venom toxin from the Loxosceles intermedia spider. The engineered
protein is not itself toxic, and gives effective protection against the effects
of the pure spider venom in animal models.
"In Brazil we see thousands of cases of people being
bitten by Loxoscelesspiders, and the bites can have very serious
side-effects," said Dr. Chávez-Olortegui, corresponding author of the
study. "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
Current approaches to protecting against venom involve
giving the venom to animals, and taking the resulting antibodies for the serum.
These antibodies enable the human immune system to prepare to neutralize venom
from bites. Although they are somewhat effective, the production of anti-venoms
like these is problematic because animals are required to produce them, and
these animals suffer from the effects of the venom.
The new protein is engineered in the lab, without the need
for the venomous animals. It is made up of three proteins, so it can protect
against more than one kind of toxin at a time. The protein is not harmful to
the immunized animal that produces the antibodies. It is also more effective
than existing approaches, and easier to produce than preparing crude venom from
"It's not easy taking venom from a spider, a snake or
any other kind of venomous animal," said Chávez-Olortegui. "With our
new method, we would be able to engineer the proteins in the lab without having
to isolate whole toxins from venom. This makes the whole process much
Tested on rabbits
The researchers tested their new protein on rabbits: all
immunized animals showed an immune response similar to the way they respond to
the whole toxin. The engineered protein was effective for venom of the L.
intermediaand L. gaucho sub-species, which have similar toxins. Immunized
rabbits were protected from skin damage at the site of venom injection, and from
This engineered protein may be a promising candidate for
therapeutic serum development or vaccination in the future.