Scientists have created an aging clock for immune cells

Over time, the body’s defenses weaken: infections become more dangerous, vaccinations work less well, and the risk of developing autoimmune diseases increases. Scientists from the Center for Individualized Infection Medicine (CiiM) (Germany) decided to find out exactly what changes occur in immune cells and whether they can be influenced.

Machine learning and data on more than 2 million immune cells obtained from blood samples of 1000 healthy people aged 18 to 97 years were used for the analysis. Using this data, they created a computer model of the Single-Cell Immune Aging Clock, a clock system that tracks how age affects different types of immune system cells.

The study showed that the activity of a number of genes in immune cells changes with age. It is these genes that play a key role in the inflammatory processes that often accompany aging. This supports the theory that immune aging is linked to chronic inflammation in the body.

Using the new method, the scientists studied how infections and vaccinations affect age-related changes in immune cells. In patients with severe COVID-19, only one cell type, monocytes, was affected by aging. However, three weeks after recovery, their condition began to return to normal.

Vaccination against tuberculosis also had an unexpected effect. In people with high levels of inflammation in the body, the vaccination not only protected them, but also rejuvenated one type of T-lymphocyte.

The model developed opens up new possibilities for studying immunity. It is now possible to better understand how to slow cell aging, improve the effectiveness of vaccinations, and develop ways to maintain health in old age. Scientists hope that their work will help to create new methods of preventing diseases associated with age-related changes in the immune system.