Every four months, pathologist Aaron LeBeau scoops into a net one of the five nurse sharks he keeps in his University of Wisconsin lab. Then he carefully administers a shot to the animal, much like a pediatrician giving a kid a vaccine. The shot will immunize the shark against a human cancer, perhaps, or an infectious disease, such as Covid-19. A couple of weeks later, after the animal’s immune system has had time to react, LeBeau collects a small vial of shark blood.
Halfway across the country, immunologist Hidde Ploegh goes through the same steps, but with alpacas that live on a farm in western Massachusetts. The scientists are after the same thing: tiny antibodies, made only by certain animals, that may have big implications for human health.
Most antibodies — those molecules that course through our blood and tissues patrolling for pathogens — are fairly hefty as proteins go. But the antibodies made by camels and sharks and their close relatives are simpler and smaller. Since their discovery in the late 1980s, researchers have learned that these antibodies pack a big punch: They can latch onto hidden parts of molecules and can penetrate tissues more deeply, enhancing their potential as therapies.
“They can get into little nooks and crannies of different proteins that human antibodies cannot access,” LeBeau says.
In the last decades, investigations of these diminutive antibodies have surged. Not only can they sneak into small places, they are also easy to work with — sturdier than their ordinary counterparts — and relatively cheap to make in large quantities. All these features make the antibodies promising treatments for a host of diseases, whether clotting disorders or Covid-19. Researchers are also exploring their use for diagnosing conditions such as cancer, and they’re becoming a key tool in other kinds of research, like mapping cells’ insides.
