Design of a Heterobivalent Ligand to Inhibit IgE Clustering on Mast Cells
That is a new study of scientists from the University of Notre Dame promising now inhibits allergic reactions without side effects.
The study has been considered as a breakthrough method for allergy treatment that prevents food allergies, drug allergies, and asthmatic side effects without suppressing a sufferer’s entire immunological system.
The therapy centers on a particular molecule the investigators designed, a heterobivalent ligand (HBL), which when introduced into a person’s bloodstream may, essentially, out-compete allergens like egg or peanut proteins in their race to attach to mast cells, a kind of white blood cell which is the resource of type-I hypersensitivity (that is, allergy).
“Unlike most current treatments, this approach keeps allergic reactions from happening in the first place” says Basar Bilgicer, assistant professor of Chemical and Biomolecular Engineering and Chemistry and Biochemistry and principal investigator in Notre Dame’s Advanced Diagnostics & Therapeutics initiative.
Michael Handlogten, lead scientist on the paper and a graduate student in Dr. Bilgicer’s group, explained that among the various chemical functionalities he analyzed to be used as the scaffold HBL synthesis, ethylene glycol, an FDA-approved molecule, proved to be the most promising.
Mast cells are part the human body’s defense against parasites (such as tapeworms), and when working normally they are attracted to, attach to, and annihilate these pathogens. But type-I hypersensitivity occurs when the cells react to non-threatening substances. More common allergies are caused by ambient stimulants, and an allergic response may range from a mild itch to life-threatening anaphylactic shock.
Tanyel Kiziltepe, a research professor in Advanced Diagnostics & Therapeutics, adds that “anaphylaxis can be attributed to certain food allergens, insect stings, antibiotics, and some medicines, and we believe HBL has a very high potential to be developed as a preventative medication.”
While many medicines treat allergies by weakening a person’s entire immune system, this approach only disrupts the process whereby white blood cells bond with allergens in the first place.
“It also does not leave patients open to an increased risk for infections or the development of cancers,” explains Bilgicer. “HBLs might be most useful in situations where it’s not possible to speak to or gauge someone’s sensitivity.”
“For example, in an emergency, on a battlefield, or in a remote location, doctors may not be able to ask a patient about an allergy before administering penicillin. An engineered HBL could be given along with the medicine and perhaps prevent a deadly reaction from occurring.”
In a normal allergic reaction, allergens bind to a white blood cell, or “mast” cell, and cause the release of inflammatory molecules. Scientists at Notre Dame have shown how non-allergenic molecules, named heterobivalent ligands, can be created to attach to mast cells first, blocking the allergic reaction in the first place.