Ageing mice study finds why 'zombie cells' evade immune clearance and fuel inflammation

Experiments in mice found that declining CMA affects senescent cells and the macrophages that clear them. (Representational photo) Researchers studying ageing in mice have identified a cellular process that may help explain why what are called 'zombie cells' become harder for the body to remove as it gets older. The new study led by researchers at Albert Einstein College of Medicine and published in Nature Aging, found that a decline in a cellular recycling system affects both these damaged cells and the immune cells responsible for clearing them.The cells, formally known as senescent cells, are living cells that have stopped dividing or functioning normally but remain in tissues. Their accumulation has been linked to chronic inflammation and age-related diseases.During the study, researchers focused on chaperone-mediated autophagy, or CMA, a cellular recycling process that identifies damaged or unnecessary proteins and breaks them down. CMA uses specialised 'chaperone' molecules to target proteins for digestion. Previous research led by Ana Maria Cuervo had found that CMA activity declines with age and that reduced activity can allow unwanted cellular material to accumulate.The la...