Immune cells in the blood drive cognitive ageing — blocking them improves memory0

• SCIENCE
• May 14, 2026

Age-related memory decline could be caused by ageing immune cells.Credit: JasonDoiy/Getty A type of immune cell circulating in the blood contributes to cognitive ageing, and blocking its effects can reverse the changes, suggests a mouse study published in Immunity on 14 May1. T cells have many jobs, chiefly destroying pathogens. But as people age, a