Scanning electron micrograph of an adult T from the immune system of a healthy donor. Credit: NIAID
Key points:
- Researchers have shown that newborns’ T cells outperform adult T-cells at fighting off numerous infections.
- While adults T cells use adaptive immunity—recognizing specific germs to then fight them later—newborn T cells are activated by proteins associated with innate immunity.
- The results help clarify why adults and infants respond differently to infections and pave the way for controlling T cells’ behavior for therapeutic applications.
We often think of newborns as especially fragile. And while that’s true in most circumstances, new research has revealed a surprising exception.
Cornell University scientists have shown that newborns’ T cells—white blood cells that protect from disease—outperform those of adults at fighting off numerous infections. Scientists have long believed that a newborn’s immune system was an immature version of an adult’s, but this new study shows that may not be true.
The results help clarify why adults and infants respond differently to infections and pave the way for controlling T cells’ behavior for therapeutic applications.
In the study, published in Science Immunology, researchers discovered that newborn T cells are involved in a part of the immune system that does not require antigen recognition: the innate arm of the immune system. While adults T cells use adaptive immunity—recognizing specific germs to then fight them later—newborn T cells are activated by proteins associated with innate immunity.
“Our paper demonstrates that neonatal T cells are not impaired, they are just different than adult T cells and these differences likely reflect the type of functions that are most useful to the host at distinct stages of life,” said study author Brian Rudd, associate professor of microbiology and immunology at Cornell.
Neonatal T cells can participate in the innate arm of the immune system. This enables newborn T cells to do something that most adult T cells cannot: respond during the very first stages of an infection and defend against a wide variety of unknown bacteria, parasites and viruses.
Following up on the discovery, Rudd said he wants to study the neonatal T cells that persist into adulthood in humans.
“We are also interested in studying how changes in the relative numbers of neonatal T cells in adults contributes to variation in the susceptibility to infection and outcomes to disease,” he said.