Scientists at The University of Nottingham
have discovered a new molecule that could offer the hope of new treatments for
people allergic to the house dust mite.
The team of immunologists, led by Amir
Ghaem-Maghami, MD, and Professor Farouk Shakib in the University’s School of Molecular Medical
Sciences, have identified the molecule DC-SIGN
which appears to play a role in damping down the body’s allergic response to
the house dust mite.
The molecule can be found on the surface of
the immune cells which play a key role in the recognition of a major allergen
from house dust mites called Der p 1, a leading cause of asthma in northern Europe. The recognition of the allergen by the immune
system is thought to lead to on-going sensitization and the development of
allergic symptoms.
The discovery furthers our understanding of how the body’s
immune system identifies and reacts to allergens, which could ultimately pave
the way for developing new therapies or treatments for preventing allergies.
Good news for
sufferers
It’s especially good news for the millions of people with asthma whose
condition is worsened by their allergy to house dust mite and other
environmental allergens. House dust mite droppings contain a whole raft of
allergens that trigger a reaction when they become airborne and are inhaled.
Ghaem-Maghami said: “There has been a sharp increase in the
prevalence of allergies over the past few decades and allergic asthma among
children has reached epidemic proportions in many industrialized countries, including
the U.K.
Despite improvements in patient care, mortality and morbidity of allergic
asthma has remained high, and most therapies target symptoms rather than curing
the condition.
“Many people with asthma are highly sensitive to airborne
allergens such as those from house dust mite—in fact, many studies have shown
that up to 80% of people with asthma are allergic to house dust mite.
“A better understanding of how the interaction between
allergens and the immune system triggers allergy is vital if we are to develop
more effective and efficient treatments for this debilitating condition.”
Inflammatory response
Allergy is a disorder caused by the body’s immune system reacting to
harmless substances found in the environment, known as allergens. Believing
itself under attack, the immune system produces an antibody called IgE, which
eventually leads to the release of further chemicals (including histamine) by
certain immune cells, which together cause an inflammatory response and the
classic symptoms of allergy—itchy eyes, sneezing, runny nose, and wheezing.
The Nottingham work,
published in the Journal of Biological
Chemistry, has focused on the role of DC-SIGN, a receptor found on the
surface of antigen presenting cells. These cells are among the first cells in
the immune system that come into contact with allergens.
The team found that DC-SIGN binds to major allergen from
house dust mite (Der p 1) and dogs (Can f 1) and seems to play a regulatory
role in the allergic response to house dust mite allergens. The binding of
allergen to DC-SIGN on antigen presenting cells seems to promote a mechanism
that could dampen harmful immune responses to allergens.
This is opposite to the role of another allergen reception—the
mannose receptor—that has previously been identified by the Nottingham
group.
The discovery shows that DC-SIGN could potentially play a
beneficial role in regulating immune responses to environmental allergens.
SOURCE
