Engineered Brain Cells Show Promise in Clearing Alzheimer’s Plaques

A novel cellular immunotherapy is demonstrating significant potential in combating Alzheimer’s disease, according to a new study published in Science. Researchers have engineered brain cells to effectively clear amyloid plaques, a hallmark of the disease, in mice. The approach offers a potential long-term solution with the possibility of a single treatment, contrasting with current therapies that require frequent infusions.

How the New Therapy Works

The research team at Washington University School of Medicine in St. Louis focused on astrocytes, star-shaped brain cells that provide support to neurons. They genetically modified these astrocytes using a specially engineered virus to equip them with a chimeric antigen receptor (CAR) – a “homing device” – that targets and binds to amyloid beta plaques. This transforms the astrocytes into highly efficient “super cleaners” that actively remove the damaging proteins from the brain.

This method draws inspiration from CAR-T cell therapy, a successful cancer treatment where immune cells are engineered to attack tumor cells. However, instead of modifying immune cells, this new approach reprograms brain cells themselves.

Study Results in Mice

The study yielded promising results in mice genetically predisposed to developing amyloid plaques. A single injection of the engineered astrocytes prevented plaque formation in young mice over a six-month period. Even in older mice that already had established plaques, a single treatment reduced the amount of amyloid plaques by approximately 50% over three months [1].

These findings are particularly encouraging when compared to existing amyloid-clearing antibody drugs like lecanemab and donanemab, which require frequent intravenous infusions (every two to four weeks) and can have potential side effects [4].

Potential Advantages and Future Directions

Whereas current antibody treatments can extend independent living for Alzheimer’s patients by roughly 10 months [1], the new immunotherapy offers the potential for a more durable effect with a single procedure. Researchers emphasize that, like antibody therapies, the engineered astrocytes are likely to be most effective in the early stages of the disease.

“This study marks the first successful attempt at engineering astrocytes to specifically target and remove amyloid beta plaques in the brains of mice with Alzheimer’s disease,” said Marco Colonna, MD, the Robert Rock Belliveau, MD, Professor of Pathology at WashU Medicine [1].

Further research is crucial to optimize the approach and address potential side effects before clinical trials in humans can begin. However, the results suggest a promising new avenue for treating not only Alzheimer’s disease but also potentially other neurodegenerative diseases and even brain tumors [2].

Understanding Alzheimer’s Disease and Amyloid Plaques

Alzheimer’s disease is characterized by the buildup of amyloid beta protein, which forms plaques in the brain. These plaques disrupt brain function, leading to atrophy and cognitive decline [1]. Removing these plaques is a key therapeutic target in the fight against the disease.