McGill University Health Centre
With the arrival of spring, millions of us have begun the annual
ritual of sneezing and wheezing due to seasonal allergies.
A research team at
the Montreal Children's Hospital from the Research Institute of the McGill
University Health Centre (RI-MUHC) is bringing them hope with a potential
vaccine that nudges the immune response away from developing allergies.
The
findings published in the journal Mucosal Immunology have
major clinical implications since allergies and asthma are lifelong conditions
that often start in childhood and for which there is presently no cure.
"Our study, for the first time, offers a potential way of preventing allergies by using a molecule that redirects the immune response away from the allergic response," says lead author Dr. Christine McCusker, allergist at the Montreal Children's Hospital and researcher at the RI-MUHC. "This discovery is very promising since the molecule we developed can be administered by a drop into the nose as a spray."
It is estimated that 20 to 30 per cent of the Canadian
population suffers from a range of allergies. Recent research reported that one
in every 13 Canadians suffers from a significant food allergy. The reasons why
allergies develop remain unexplained, but it is believed that all children are
born with the potential to develop allergies.
Children without allergies make a
shift to the non-allergenic immune response when allergens are around. Those
who do develop allergies have not shifted by the time they are exposed to the
allergen.
Dr. McCusker and her team from the Meakins-Christie Laboratories
started to work on a specific molecule -- called STAT6 -- which is important in
the development of allergic response.
They thought that if they could inhibit
this molecule they would reduce the symptoms of allergic airways disease, such
as asthma, in allergic animals.
They also hoped to prevent the allergy from
developing entirely. To do this, they developed an inhibitor peptide called
STAT6-IP that was given to newborn mice by intranasal droplet.
"By giving the peptide STAT6-IP very early on, before
allergies are present, we were able to teach the immune system. So when we
tried to make the mice allergic later on, we couldn't because the immune system
had 'learned' to tolerate allergens," explains Dr. McCusker who is also an
associate professor in the Department of Pediatrics at McGill University.
"What's beautiful about our approach is that you do not
have to couple it with a specific allergen, you only use this peptide. It just
redirects the immune system away from the allergic response and then it will
not matter if the child is exposed to pollen, cats or dogs, because the immune
system will not form an aggressive allergic reaction anymore," adds Dr.
McCusker.
"In subjects who have the propensity to develop allergies,
their system has made the 'wrong' decision somewhere along the line," she
says. "It is like educating the immune system to follow the path we want
it to follow."
Researchers are now studying the effect of this peptide to see
in what other areas this type of immune education will prevent disease, such as
with food allergies. They then hope to move this discovery to clinical trials
in humans.