Researchers at Washington University engineered astrocytes expressing chimeric antigen receptors (CAR‑As) that prevented amyloid‑β plaque formation when given prophylactically and reduced established plaque burden by about half with a single injection in Alzheimer’s mouse models. The Science paper from Marco Colonna’s team details in‑brain cellular immunotherapy that leverages astrocytes’ abundance and longevity as an alternative to repeated antibody dosing. The authors note additional work is required to optimize delivery, dosing and safety before translational steps; CAR‑As represent a cell‑based approach distinct from monoclonal antibody strategies. CAR‑astrocytes may offer a path to durable central nervous system immunotherapies if peripheral and on‑target/off‑target risks can be managed.