Scientists Discover Protein That Can Rejuvenate The Ageing Immune System
A breakthrough from the University of Illinois Chicago offers promising avenues to combat age-related immune decline by rejuvenating ageing blood stem cells. Researchers led by Associate Professor Sandra Pinho identified that platelet factor 4, a blood protein, plays a crucial role in regulating the ageing of hematopoietic stem cells (HSCs), which are responsible for producing blood and immune cells.
Hematopoietic stem cells reside in bone marrow and generate two primary types of blood cells: myeloid cells, including red blood cells, and lymphoid cells, notably T and B cells responsible for immunity. With age, stem cells tend to produce fewer lymphoid cells and more myeloid cells, leading to altered immune responses and weakened defence against infections. This shift partly explains why older individuals have less effective immune systems.
The study revealed that young individuals maintain higher levels of platelet factor 4, which serves as a molecular messenger restricting excessive division of myeloid-biased stem cells. However, ageing causes a decline in platelet factor 4 levels, permitting uncontrolled stem cell proliferation, accumulation of mutations, increased inflammation, and heightened risk of blood cancers and cardiovascular diseases.
Crucially, supplementing older mice and human stem cells with platelet factor 4 restored youthful behaviour in these cells. Daily infusions in mice for over a month reversed markers of ageing in the blood and immune systems. In laboratory experiments, platelet factor 4 treatment rejuvenated human ageing stem cells, enhancing their function.
Though not a universal cure for ageing, this discovery points to platelet factor 4 as a compelling candidate in developing therapies targeting age-related disorders. The research aligns with Zimbabwe’s objectives to incorporate cutting-edge science into improving elderly health and resilience against diseases.
FFA Explainer Box
“Hematopoietic stem cells (HSCs) are rare cells in the bone marrow that generate all types of blood and immune cells, essential for maintaining a healthy immune system.”
Integrating such innovations with efforts like Zimbabwe’s National Development Strategy to support healthy ageing populations can enhance community wellbeing and reduce healthcare burdens. By harnessing the body’s own molecular mechanisms, the future of regenerative medicine looks promising for the African continent and beyond.
Reference: Zhang, E. et al. (2025). Platelet factor 4 regulates hematopoietic stem cell aging. Blood. DOI: 10.1182/blood.2024027432
About The Author
