Researchers don’t yet know why some juvenile rheumatoid arthritis, or JRA, patients have defective NK cells, Dr. Yokoyama says. NK cells in people with JRA risk factors might somehow be inhibited from controlling infections, he says.

Dr. Yokoyama, who’s been elected to the National Academy of Sciences and the American Academy of Arts and Sciences in recognition of his research, is careful not to overpromise what his discoveries might mean for people with arthritis. But because NK cells get rid of viruses, Dr. Atkinson says many researchers are eager to see how they will play out in other diseases, such as lupus and rheumatoid arthritis.

“The basic science is so impressive that it sort of overwhelmed any immediate application,” Dr. Atkinson says.  “One of the theories is that these NK cells are responsible for some of the damage we see in an infected joint or lupus kidney or psoriatic skin or rheumatoid joint,” he continues. “I envision blocking NK cells to prevent damage we see in a joint.”

Since he’s shown that receptors both block and activate NK cells, Dr. Yokoyama hopes he’s giving researchers more options – to either figure out what’s stimulating NK cells and stop it, or work to enhance the receptor’s inhibitory signal. He’s thrilled that investigators around the world are now looking at these cells and receptors to see what role they play in a variety of diseases and conditions.

“By understanding how NK cells work, we can apply this knowledge to other cells in the immune system,” he says. “In that sense it’s farther reaching than just how NK cells themselves work. If it’s a concept that applies to other immune cells and gives drug companies strategies to affect the immune response then that’s good.”

Dr. Yokoyama says he’s not done searching for answers either. “I’m not ready to retire. Far from it,” he says. “I’m a scientist. There’s always something more to discover.”