USING NONBODIES
TO TARGET THE VIRUS
A unique antibody produced by llamas could be developed as
a new frontline treatment against COVID-19 and could be taken
by patients as a simple nasal spray.
The research has
shown that nanobodies (a smaller, simple form of antibody
generated by llamas and camels) can effectively target the
SARS-CoV-2 virus that causes COVID-19.
It is the first
step towards developing a new type of treatment against COVID-19.
The scientists are hoping to progress this work from the animal
setting to prepare for clinical studies in humans.
The research team
found that short chains of the molecules, which can be produced
in large quantities in the laboratory, significantly reduced
signs of the COVID-19 disease. It can be administered either
nasally or by injection to infected animal models.
The nanobodies
bind tightly to the SARS-CoV-2 virus, neutralising it in cell
culture. They could ultimately provide a cheaper and easier
to use alternative to human antibodies taken from patients
who have recovered from COVID-19.
Human antibodies
have been an important treatment for serious cases during
the pandemic, but typically need to be administered by infusion
through a needle in hospital.
TESTING THE NEW
TREATMENT
The research team
published their findings in the journal Nature Communication.
They were able to generate the nanobodies by injecting a portion
of the SARS-CoV-2 spike protein into a llama called Fifi,
who is part of the antibody production facility at the University
of Reading.
The spike protein
is found on the outside of the virus and is responsible for
binding to human cells so it can infect them.
Although the injections
did not make Fifi sick, it triggered her immune system to
fight off the virus protein by generating nanobodies against
it. A small blood sample was then taken from the llama and
the researchers were able to purify four nanobodies capable
of binding to the COVID-19 virus.
The nanobodies
were then combined into chains of three to increase their
ability to bind to the virus. These were then produced in
cells in the laboratory.
EXAMINING THE
NANOBODY STRUCTURE
Professor James
Naismith, Director of the Rosalind Franklin Institute, who
helped lead the research, said:
The team found
three nanobody chains were able to neutralise both the original
variants of the COVID-19 virus and the Alpha variant that
was first identified in Kent, UK. A fourth nanobody chain
was able to neutralise the Beta variant first identified in
South Africa.
When one of the
nanobody chains (also known as a trimer) was administered
nasally to hamsters infected with SARS-CoV-2, the animals
showed a marked reduction in disease. They lost far less weight
after seven days than those who remained untreated.
Hamsters that
received the nanobody treatment also had a lower viral load
in their lungs and airways after seven days than untreated
animals.
ADAPTING TO FIGHT
DISEASES
Professor Ray
Owens, head of protein production at the Rosalind Franklin
Institute and lead author of the research, said:
The researchers
also hope the nanobody technology they have developed could
form a so-called ‘platform technology’ that can
be rapidly adapted to fight other diseases.
Dr Andrew Bourne,
Director of Partnerships at EPSRC, said:
