Highlights:
- Nanobodies which
could be used in the treatment of Respiratory Syncytial Virus (RSV)
infections is developed by a research team from Geisel School of Medicine.
- The nanobodies
are designed to bind to proteins expressed on the surface of the viruses.
- The proteins on
the virus aid in entry into the lung cells. When the nanobodies bind to
them, the viruses are prevented from entering the lung cells.
Respiratory syncytial
virus (RSV) causes lung infection and affects the breathing passage. It is a
significant cause of respiratory illness among small children with no
anti-viral therapy currently available. This has created an urgency to identify drug
therapy for treating the infection caused by this virus. The Geisel School of
Medicine's research team and other research collaborators identified a new
method of antiviral therapy against respiratory syncytial virus.
Nanobodies
The technology developed
by the scientists target and neutralizes proteins expressed by the virus,
blocking it from entering lung cells. This was possible by the use of
single-domain antibodies, called Nanobodies.
The study was published in the journal
Nature Communications, detailing the interaction of the Nanobodies
with the viral proteins and neutralizing them, along with their success in
protecting mice from RSV infection and the associated inflammation.
‘Nanobodies could soon provide the first- ever therapy for respiratory syncytial virus infections’
Producing Nanobodies
The scientists
collaborated to generate and purify Nanobodies which targeted the unstable but
active form of the RSV protein. On a more detailed study, it was found that
these Nanobodies were closely associated with a conserved region of the viral
protein, resulting in anti-viral reaction against different types of RSV.
Dr. Xavier Saelens said
that the scientists were successful in designing molecules which resulted in a
potent reaction against RSV, in numerous clinical isolates in laboratory cell
culture as well as in animals. The Nanobodies that were developed by these
scientists have thus far been the most effective against RSV.
The small size of the
Nanobodies allowed them to get attached to cavities that are present on the
surface of the viruses, which prevented the viruses from entering cells in the
lung.
Novel therapy against
RSV
Nanobodies are
attractive as a method of therapy since they
- Are Stable
- Can be
administered easily to the lungs
- Are Soluble
- Provide quick
treatment
- Could be used to
prevent hospitalization due to RSV
- Lower distress
caused to patients
- Minimizes cost
Respiratory Syncytial
Virus (RSV)
In healthy people this
virus could lead to flu-like symptoms that may be mild. However, in infants as
well as in older adults, RSV infection can be serious.
- It is the most common cause of bronchiolitis, which is an inflammation
of the lung airways
- It Is also the most common reason for
pneumonia in children younger than 1 year of age(U.S).
- It results in 34 million illnesses among
children below the age of 5 years.
- Two percent of cases require
hospitalization.
- Treatment methods that are available are
restricted to supportive care
- RSV is highly contagious, spreading via
droplets infection when someone coughs or sneezes.
- The virus survives surfaces which include
door knobs as well as counter tops
- It spreads among children in day care
centers and older children pass it on to their younger siblings at home.
- In the U.S, it is found that almost all the
children are affected by this viral infection, atleast once, by the time
they are 2 years old.
These infections
sometimes take epidemic proportions and are commonly found during the months
from late fall to spring. Some children may not be severely affected while
others could develop a very serious condition.
Dr. Prof. Xavier
Saelens says that the scientists had a
goal of developing a novel method of treatment for this infection. This gave
rise to the design of Nanobodies which were focused on the viral protein that
was required by the virus to enter the cells of the lung. The Nanobodies were
found to neutralize RSV, both in animal studies as well as in laboratory
assays.
Making Way for
Clinical Tests
The Nanobodies are being
altered into a form which can be used in clinical trials, which will aid in
understanding its significance among the general public. The scientists claim
that they will not be working on developing a usable form of Nanobodies on
their own, instead, they are looking at industrial support which will aid in
better solutions for patients with RSV.
Nanobodies are
antibodies that are antigen-specific, recombinant and contain a single domain.
They have a renewable source of reagents and have high production of a variety
of expression systems. They are small in size, can dissolve easily in aqueous
solutions and can recognize unique epitopes (part of the antigen molecule
attached to the antibody itself). They are currently being used for a variety
of research purposes but this is the first study to use Nanobodies in the
treatment for RSV patients. This would provide a highly specific therapy for
the deadly infection, aiding in an effective therapy.
References:- Respiratory Syncytial Virus Infection
(RSV) - (https://www.cdc.gov/rsv/)
- About
RSV - (http://kidshealth.org/en/parents/rsv.html)
- Nanobodies and their potential applications
- (https://www.ncbi.nlm.nih.gov/pubmed/23730699)
Source: Medindia
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