A graduate student at the Hebrew University of Jerusalem may have come up with a novel method for ridding the body of allergies and asthma, according to a report released by ScienceDaily. Ido Bachelet, a Ph.D. student, was awarded this year’s Barenholz Prize for Creativity and Originality in Applied Research for his ingenious approach to the eradication of the allergic response, which until now has no real cure.
While allergy is viewed as more of an annoyance than a serious disease, globally, over 250,000 individuals died from allergic response in 2005 alone. Death is due largely to complications from conditions such as asthma, and lethal shock reactions to food and snake and insect venoms.
The main culprits of the allergic response are mast cells. These cells, also called mastocytes, reside in loose connective tissue and contain many fine granules composed of histamine and heparin.Upon exposure to pathogens, mast cells release the contents of their granules, causing symptoms such as stuffy nose, rash, and even airway constriction. These symptoms are a necessary part of immune defense and wound healing, but they can easily escalate out of control with exposure to common allergens such as pollen. Furthermore, the mast cells attract other inflammatory cells, which serve to maintain the immune response at chronic levels.
Bachelet first identified a key receptor found on the surface of mast cells, termed CD300a. When engaged, this receptor “turns off” mast cell activity. Unfortunately, the receptor is also found on other immune cells, so targeting just the receptor alone can result in general immune suppression.
To work around this issue, Bachelet and his colleague, Ariel Minitz, designed a synthetic antibody that is able to bind not only the CD300a receptor, but also a marker specific to mast cells themselves. This allows the antibody to bind specifically to mast cells, not just general immune cells.
When tested on mice exposed to various allergens, the antibody was able to eradicate at least four allergic diseases in the mice. The antibody, when administered in nose drops, also eliminated severe chronic asthma in the mice in the space of about two months.
Bachelet and his colleagues are hopeful that this antibody will be used for allergy treatment in the future.
Other groups have also used small immune molecules with success. Back in 1998, a group at the National Jewish Medical and Research Center used an inhaled form of synthetic interleukin (IL)-4 receptor molecules to stem the allergic response in both mouse and human subjects. IL-4 is another player involved in the immune response, and when attached to its receptor, induces the production of immunoglobin (Ig) E. IgE goes on to produce the classic symptoms of allergy. By inhaling the receptor, excess IL-4 is thought to be “mopped up” and prevented from reaching target IL-4 receptors on immune cells.
The IL-4 treatment, while effective, does not last long (about 8 days) and needs to be reapplied weekly. Antibodies to CD300a may last much longer, with effectiveness measured out to at least two month’ time.
Sources:No More Choking And Burning Eyes? New Approach To Eliminating Allergies, Asthma http://www.sciencedaily.com/releases/2007/06/070627110605.htm
Artificial Il-4 Receptor Could Stop Allergies, Help People With Allergic Asthma http://www.sciencedaily.com/releases/1998/05/980508101131.htm