Chinese scientists identify key factor that slows immune ageing

Chinese researchers have achieved a significant scientific breakthrough by identifying a crucial factor that can slow the ageing of immune cells and by developing a novel method to measure the biological age of the human immune system. According to  Xinhua News Agency, the findings offer promising prospects for enhancing health in later life and preventing age-related diseases.

Understanding how quickly the immune system ages has long posed a challenge due to its complexity. To address this, scientists analysed blood samples from 230 healthy individuals covering a 60-year age span. Using advanced single-cell technologies, they created a high-resolution map of nearly 1.2 million peripheral blood mononuclear cells, identifying 24 distinct immune cell subtypes.

Based on this dataset, the researchers developed the Human Immune Ageing Clock (HIAC) – a pioneering analytical tool capable of estimating an individual’s immune age with an average error margin of just 5.66 years. This innovation provides a valuable benchmark for assessing immune health and monitoring the effectiveness of future therapies.

The study revealed that T cells, which play a central role in defending the body against infections, are particularly sensitive indicators of immune ageing. As individuals grow older, the number of naïve T cells – responsible for responding to new pathogens – declines, while exhausted T cells and monocytes increase.

A critical turning point was identified at around the age of 40, when immune ageing accelerates. Most notably, the researchers discovered that the protein RUNX1 is essential for maintaining the youthful function of T cells. Levels of RUNX1 decrease with age, leading to diminished immune performance.

Experimental findings demonstrated that removing RUNX1 from young T cells caused them to exhibit characteristics of ageing. Conversely, enhancing RUNX1 levels in older T cells restored their functionality, enabling them to better combat infections. These results were further validated in mouse models, confirming the protein’s role in rejuvenating immune responses.

This breakthrough opens new avenues for the development of treatments designed to strengthen immunity in older populations, potentially reducing vulnerability to infections, chronic diseases, and age-related health complications.

The study was conducted by a team from the China National Center for Bioinformation, the Institute of Zoology under the Chinese Academy of Sciences, and the Quzhou Affiliated Hospital of Wenzhou Medical University.