An experimental
therapy to freeze the molecular process that triggers allergic reactions
is showing promise in animal studies and could be a potential treatment
for humans, researchers reported.
Researchers at the University
of California at Los Angeles and the University of New Mexico designed
a genetically engineered molecule called GE2 that interacts with two types
of immune system cells playing key roles in allergic reactions -- basophils
and mast cells.
The cells respond
abnormally to substances such as pollen or animal dander and cause the
body's histamines to go into overdrive.
Excessive histamine
is what leads to allergy symptoms such as runny nose, swelling, and inflammation.
Andrew Saxon,
lead researcher and director of UCLA's Asthma, Allergy, and Immunologic
Disease Center, explained that the experiment attached GE2 to receptor
molecules that control histamine release by the basophils and mast cells.
One of the receptor molecules works like a gas pedal by triggering the
allergic reaction, Saxon said. The other receptor molecule works like a
brake. GE2 was constructed to push the brake and gas pedals the same time,
thereby paralyzing the process that ignites an allergic reaction.
"What we're
doing is sort of locking that receptor down with another receptor that
shuts that cell off," Saxon told United Press International.
Laboratory tests
on human mast cells and basophils showed the higher the GE2 dose, the less
histamine the cells released when stimulated by allergens. Mice tests showed
GE2 significantly cut down allergic skin reactions.
The findings
are published in the May issue of Nature Genetics.
Saxon said
the next step is to study this therapy in primates. It is possible the
approach could be used to treat allergic asthma, rhinitis or inflammation
of nasal passage mucus, hives, and even potentially lethal anaphylaxis
brought on by severe allergic reactions to certain foods such as peanuts.
Lanny Rosenwasser,
head of allergy and clinical immunology at the National Jewish Medical
and Research Center in Denver and president-elect of the American Academy
of Allergy, Asthma and Immunology, told UPI this technique has "a low probability
of being successful in impacting patients."
"GE2 is a signaling
protein that can be re-engineered so that it doesn't signal," Rosenwasser
explained. This study is useful because "the more we learn about signaling
and knowing more on how we can inhibit signaling, the better off we'll
be."
Making this
approach an actual clinical therapy, Rosenwasser said, is "a stretch."
But, "understanding this process may lead to significant improvements in
the future. ... This is an excellent study."
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