As a class, antibody receptors allow immune system cells to affix antibodies onto the cells' surface to act as antennas for antigens, or foreign triggering substances. When triggered, the cells respond by unleashing a barrage of immune responses. Other members of the antibody receptor family are involved in tumor recognition, autoimmune diseases such as arthritis, and in normal immunity. An estimated 20 percent of the population suffers from allergies. Asthma afflicts 15 million people in the U.S. and causes 500,000 hospitalizations and 5,000 deaths each year.
Current treatments block the action of the signal molecules or the inflammation they cause.
But knocking out the master switch could be more effective than trying to impede all the signals the mast cell sends out, said Theodore S. Jardetzky, the Northwestern X-ray crystallographer who led the study. Several pharmaceutical and academic teams had been trying to study the receptor by expressing its gene in cultured cells. But the receptor protein that researchers obtained from these cells had stubbornly defied all attempts to solve the crystal structure. The resolution of the determined structure is 2.4 angstroms.