Mini-Antibodies Discovered in Sharks and Camels Could Lead to Drugs for Cancer and Other Diseases

Helen Dooley admits that she often gets puzzled responses when she describes her work. “People say, ‘You bleed sharks for a living?’”

That’s an overstatement, but every couple of weeks she and a helper drop by several large fiberglass tanks at the Institute of Marine and Environmental Technology on the Inner Harbor in Baltimore, Maryland. They net a cat shark or nurse shark and wrestle it into a small pool of water that contains a mild sedative. The drug calms the shark so they can lift it from the water and puncture a vein in its tail. Drawing a few milliliters of blood “doesn’t take more than a few seconds,” Dooley says, after which they return the animal to its aquarium to recover. “They’re usually swimming about perfectly normally, and looking for food, after only a minute or so.”

Dooley, an immunologist at the University of Maryland (UMD) School of Medicine in Baltimore, has been tapping shark blood for 2 decades for the same reason that other researchers have been draining the veins of llamas, camels, and their relatives. All those animals pump out unusual, diminutive antibodies that are only about half the size of the conventional versions.