Engineered immune cells target Alzheimer's disease protein in mice

A Washington University team engineered CD4 CAR-T helper cells that bound amyloid beta and reduced plaques in the meninges of mice; the study used temporary dosing over four weeks and authors say much more work is needed before testing in people.

Researchers at Washington University adapted CAR-T methods used in cancer to target amyloid beta, the protein that forms plaques in Alzheimer's disease. The team engineered CD4 T helper cells to carry a plaque-binding receptor derived from an existing Alzheimer's treatment. Results were published in the Proceedings of the National Academy of Sciences on Feb. 9, 2026 and describe tests conducted in mice. The modified cells bound plaques and were associated with reductions in several disease markers. Key findings: - The research group engineered CD4 CAR-T helper cells using a plaque-binding region from an existing treatment. - In laboratory tests the modified cells bound amyloid beta and responded to plaque. - When given to mice, the injections reduced plaques in the meninges and increased movement of T cells into deeper meningeal and brain tissue. - The team used temporary cell alteration with three doses over four weeks and observed reductions in plaques, brain immune activation, and markers of neuronal damage. Summary: The study provides a proof of concept that engineered T helper CAR-T cells can bind and reduce amyloid plaques in mice and influence immune activity in the meninges and brain. Authors state that much work remains and that testing in people is not imminent; the timeline and next steps are undetermined at this time.