University of Georgia

Disease-fighting organ fails with age, UGA researcher is changing that

Photography By Peter Frey
University of Georgia researcher Nancy Manley

The most important organ for your body’s immune system isn’t working well anymore.

And, so far, modern medicine hasn’t figured out a way to fix it.

But if the University of Georgia’s Nancy Manley has her way, it won’t stay that way for long.

The thymus is an organ most people have never heard of, but it serves a vital purpose. The thymus produces the body’s T cells, which serve as the immune system’s front line against disease.

The thymus is most functional when you’re born. By the time you’re a teenager, it starts to go downhill.

“When I talk to audiences, I ask people, ‘How many people in the room are over 30?’ And it’s usually most of the people in the room,” says Manley, Distinguished Research Professor of Genetics. “I’m like, ‘Okay, your thymuses are all gone. You’re already too late.’”

Luckily, the T cells your body produced during childhood are good for decades, but all bets are off after that. And if the thymus is no longer producing new T cells, that means your body is more susceptible to disease. That decline in immune function is why people over 65 are more likely to become severely ill or even die when they catch the flu. And it’s been linked to the development of autoimmune diseases, cancer and neurodegenerative diseases like Alzheimer’s.

But nobody’s quite sure why or how the thymus starts deteriorating in the first place.

“We don’t know for sure how many of the problems of old age are caused by declining immune function … If we could figure out a way to make it better, we could potentially impact the longevity and health of everybody on the planet.”

– Nancy Manley, Distinguished Research Professor, Genetics

That’s where Manley’s lab comes in. As one of only a handful of labs in the world focusing on the thymus, Manley’s team is trying to figure out the basic biology of the thymus and how aging affects the organ. Their goal is to determine how T cells develop and what happens to make their numbers decline.

Combining old and new methods, Manley is able to identify genes that affect the functioning of the organ, and the technique has given the lab 18 new leads on what might be contributing to the thymus’s decline. In addition, new technology, called single-cell RNA sequencing, is enabling the team to see what individual cells in the organ are producing to determine how they work together to make the thymus function.

“We don’t know for sure how many of the problems of old age are caused by declining immune function, but we have a fairly good idea that it’s an awful lot of them,” says Manley, who also serves as the head of UGA’s genetics department. “If we could figure out a way to make it better, we could potentially impact the longevity and health of everybody on the planet.”

Nancy Manley

About the Researcher

Nancy Manley

Distinguished Research Professor & Department Head
Genetics
Franklin College of Arts & Sciences

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