Aging is a large risk factor for many of the top global killers, including heart disease, stroke, certain cancers, and Alzheimer's. Researchers have long been seeking a medication that would fundamentally change how aging occurs, effectively acting like a fountain of youth. A small step toward this goal has been achieved with a new study, which acts upon a certain genetic pathway to boost immune function in the elderly. Joan Mannick of Novartis Institutes for BioMedical Research in Massachusetts was the lead author of the paper, which was published in Science Translational Medicine.
The study focused on the pathway of mechanistic target of rapamycin, commonly referred to as mTOR. This genetic pathway is important for the healthy growth of cells and protein production, but abnormal function has been linked to several age-related diseases. Function of the MTOR pathway can be inhibited with rapamycin, which stops normal cell growth in the T-cells responsible for programmed cell death. These cells become abundant in older age.
The study itself used over 200 participants over the age of 65; an age group that makes up the bulk of influenza-related deaths each year. The test group received rapamycin, while the other was given a placebo weeks before the seasonal flu vaccine was given to all of the study participants.
The researchers found that those who had received the rapamycin and had the MTOR pathway inhibited produced 20% more antibodies in response to the flu vaccine than the control group, indicating a boost in immune function. While the effect did seem to be dose-dependent, even lower doses of rapamycin conferred an immunity boost.
While inhibiting MTOR has been known for years to extend the life of mice and other test animals, researchers need to tread carefully when translating the possible effect the drug may have with humans. Rapamycin did appear to bolster the immune system in order to stave off disease, but considerably more research is needed to understand how this plays into other effects of aging before this can be called a true anti-aging drug. The researchers caution against overstating the results of their study.
"It's very important to point out that the risk/benefit of MTOR inhibitors should be established in clinical trials before anybody thinks this could be used to treat aging-related conditions," Mannick told Dennis Thompson of HealthDay.