As we age, our immune system gradually declines, making the body more vulnerable to diseases. Recently, scientists have discovered a new method to rejuvenate a key component of the , which could potentially enhance health in older age.
A team of researchers from the Broad Institute at MIT and Harvard focused their attention on the thymus, a small organ located in front of the heart. The thymus is crucial for the development of T-cells—immune cells that act as defenders by identifying threats such as and infections.
Starting from early adulthood (ages 20 to 40), the thymus decreases in size and slows its function, limiting the production of T-cells.
“With age, the immune system begins to weaken. We wondered how to maintain immune protection over a long period,” said neurobiologist Mirko Friedrich, a co-author of the study.
How Did the Scientists Make Their Discovery?
The researchers compared the immune systems of young and old mice to identify three key signaling proteins whose levels decline with age: DLL1, FLT3-L, and IL-7. These proteins are responsible for converting cells into T-cells and supporting their function, as reported by Science Alert.
Next, the team employed a complex mRNA therapy to produce the proteins (mRNA stands for messenger ribonucleic acid). This complex was repeatedly administered to the livers of older mice, triggering the desired signaling effect.
is a powerful source of protein, even in older age. Moreover, blood draining from the stomach and intestines must pass through the liver. Accessing it during such procedures is relatively straightforward, making it an ideal target.
In older mice that received mRNA therapy for four weeks, there was a significant increase in both the quantity and diversity of T-cells. They responded more robustly to vaccinations and fought cancer tumors more effectively. These are signs of a strong, youthful, and healthy immune system.
“Our approach is more synthetic in nature. We modify the body to mimic the secretion of thymic factors,” noted neurobiologist Fen Zhang, a co-author of the study.
Importantly, the increase in T-cell production caused by the liver’s activity was temporary. This reduces the risk of overstimulating the immune system, which can lead to inflammation and the body attacking itself.
The results are promising. However, it is necessary to demonstrate the viability of this approach in other animals and humans.
Previously, scientists attempted to restore T-cell production by administering immune stimulants directly into the bloodstream. However, this often came with side effects and risks.
The new approach, which focuses on the liver, could provide a safe and effective alternative.
“If we can restore such an important part of our immune system, I hope we can help people stay healthy longer,” said Zhang.
The study’s findings were published in the journal Nature.
Photo: Unsplash
