A novel mRNA therapy is showing promise in early studies for its ability to reverse age-related decline in immune function. Researchers at teh German Cancer Research center (DKFZ) have successfully rejuvenated immune cells in aging mice by targeting T-cell production within the liver, potentially offering a new avenue for improving vaccine efficacy and cancer treatment outcomes in older adults. While still in the pre-clinical phase, the findings, published in Nature, suggest a future where regular mRNA injections could bolster the aging immune system.
The Aging Process
mRNA Injection Rejuvenates the Immune System
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As people age, their immune systems naturally decline in effectiveness. Now, a new mRNA therapy, initially tested in mice, offers a potential way to rejuvenate immune cells. This could lead to fewer illnesses in older adults and improve the efficacy of both vaccinations and cancer treatments.
Heidelberg, Germany. T-cells, or T-lymphocytes, are white blood cells and a critical component of the immune system. With age, the body produces fewer T-cells, and those that remain become less effective. This decline contributes to the increased susceptibility of seniors to age-related conditions like cardiovascular problems and chronic inflammation. Furthermore, cancer therapies that rely on the immune system to fight tumors, as well as many vaccines, often perform less effectively in older adults compared to younger individuals.
Human T-lymphocytes develop in the thymus, a small gland where they learn to recognize bacteria and viruses and distinguish them from healthy cells. Aging processes, however, cause the thymus to shrink and be increasingly replaced by fatty tissue. Researchers have previously attempted to halt this process with medications and hormones to maintain immune function, but without lasting success.
T-Cells in the Liver
Scientists at the German Cancer Research Center (DKFZ) have published a study detailing a novel approach that doesn’t directly target the thymus, but instead uses an mRNA therapy to modify T-cells within the liver.
“Most T-cells are found in the blood. And all the body’s blood flows through the liver.”
The researchers first analyzed how immune cells change during aging, identifying differences in signaling pathways and gene activity from birth through old age. They then pinpointed three key factors crucial to T-cell aging.
mRNA Therapy to Combat T-Cell Aging
To counteract the aging process in T-cells, the team, led by Mirco Friedrich, packaged mRNA – encoding the three identified proteins – into tiny fat particles. These particles accumulate primarily in the liver and were injected into mice aged 16 months (roughly equivalent to 50 human years) twice weekly.
Shortly after the mRNA therapy, the animals exhibited a significant increase in T-cell production compared to age-matched, untreated mice. Vaccines and cancer therapies also proved more effective in the treated animals. However, this effect diminished once the mRNA therapy was discontinued.
Potential Application in Older Adults
According to the scientists, further research is needed before clinical trials can begin. They must determine if the three proteins have identical functions in humans or if the mRNA needs to encode different proteins. The initial results are promising, suggesting that it may be possible to rejuvenate the human immune system with regular mRNA injections in the future.
“It is conceivable to alter the biology of T-cells in such a way that health improves significantly in old age.”
Sources:
Press release from the German Cancer Research Center (DKFZ)
Study in the journal Nature, doi: 10.1038/s41586-025-09873-4
