Blocking immune cells preserves brain tissue in Alzheimer’s mouse model, study finds

Treatment reduced T cells in the brain by half and preserved memory without removing toxic tau deposits

By LineZotpaper

Published20 October 2026

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Scientists at Washington University School of Medicine have shown that blocking a protein on immune cells can protect against Alzheimer's-related brain damage in mice, preserving roughly 40% more tissue in memory centres without clearing the abnormal tau protein thought to drive the disease. The findings, published in Neuron, suggest a new treatment strategy that targets the immune system rather than the protein deposits themselves.

The study, led by Dr David M. Holtzman and published on September 28 in the journal Neuron, focused on tauopathies, neurodegenerative conditions including Alzheimer's disease that involve the buildup of abnormal tangles of the protein tau inside brain cells.

Researchers used an antibody to block a protein called CXCR3 on T cells, which helps those immune cells enter the brain. After several months of treatment, the number of T cells inside the brains of mice with tau accumulation had fallen by approximately half.

Compared with untreated mice, treated animals retained roughly 40% more tissue in brain regions involved in memory and performed better on a memory test. These improvements occurred even though the amount of accumulated tau remained unchanged.

"In tauopathies, including Alzheimer's disease, there's no treatment right now that actually decreases neurodegeneration," said Holtzman, the study's senior author and a professor of neurology at WashU Medicine. "If we can show that we're really decreasing brain cell death, it's certainly worth trying to pursue that pathway to prevent the most devastating consequences of these diseases."

The researchers previously discovered that T cells enter the brains of mice with abnormal tau and contribute to neurodegeneration. The current study identified the CXCL10-CXCR3 signalling pathway as the mechanism guiding those T cells into the brain.

Notably, the antibody used in the study did not need to cross the blood-brain barrier to be effective. Holtzman said the approach, if proven safe, could avoid one of the major difficulties in developing neurological treatments.

The treatment has so far been tested only in mice. Holtzman noted that medications already used to control T cells in other diseases, such as multiple sclerosis, might provide a starting point for human studies.

"Tauopathies aren't thought of as autoimmune disorders, so they haven't been treated the same way, but this study shows for the first time in an animal model that these diseases respond to a specific T-cell therapy," Holtzman said.

Analysis

Why This Matters

Alzheimer's affects millions worldwide and current treatments slow cognitive decline but do not stop brain cell death.
This study offers a new potential pathway that targets the immune system rather than protein deposits, which could be effective even in tauopathies without amyloid.
The antibody's ability to work without crossing the blood-brain barrier could simplify drug development.

Background

Alzheimer's disease is a tauopathy involving abnormal tau tangles inside brain cells. Current approved treatments like lecanemab and donanemab target amyloid plaques but have not been shown to prevent neurodegeneration. Growing evidence suggests the immune system's reaction to tau, not tau itself, drives much of the damage. In 2023 researchers found that T cells enter the brains of mice with tau buildup and cause neuronal loss. The current study identifies the specific signalling pathway that recruits those T cells and shows it can be blocked.

Key Perspectives

Researchers: The approach represents a significant shift from focusing solely on abnormal proteins to also targeting damaging immune responses. The team believes existing T-cell therapies used in autoimmune conditions could be repurposed for investigation. Sceptics: The treatment has only been tested in mice. Safety and effectiveness in humans remain unknown, and translating animal model results to human Alzheimer's is historically challenging. Patients and advocates: The need for treatments that actually prevent neurodegeneration is urgent. This immunology-based strategy could open a new class of therapies if validated in human trials.

What to Watch

Whether the antibody or similar CXCR3-blocking agents enter human clinical trials.
Studies examining whether existing multiple sclerosis drugs that modulate T cells show any effect on neurodegeneration in Alzheimer's patients.
Further research confirming the CXCL10-CXCR3 pathway's role in human Alzheimer's and other tauopathies.

Sources

Scientists find a way to fight Alzheimer’s brain damage without removing toxic tau · Latest Science News -- ScienceDaily

Checked

12 claims in this story checked against 1 source: 9 supported.

Show each claim

SupportedBlocking immune cells preserved brain tissue in an Alzheimer’s mouse model.Latest Science News -- ScienceDaily: “With the pathway identified, the team tested whether blocking CXCR3 with an antibody could reduce brain damage.”
SupportedThe treatment reduced the number of T cells in the brain by about half.Latest Science News -- ScienceDaily: “By the end of the experiment, treated mice had approximately half as many T cells in their brains as untreated animals.”
Partly supportedThe treatment preserved memory.Latest Science News -- ScienceDaily: “Their performance on a memory test was also better.”
SupportedThe treatment preserved roughly 40% more tissue in memory-related brain regions.Latest Science News -- ScienceDaily: “They also showed less evidence of neuronal injury and retained substantially more brain tissue, including roughly 40% more tissue in memory-related regions.”
SupportedThe treatment left the amount of accumulated tau unchanged.Latest Science News -- ScienceDaily: “Importantly, these protective effects occurred without any detectable reduction in tau tangles.”
Partly supportedTau is thought to drive Alzheimer’s disease.Latest Science News -- ScienceDaily: “However, growing evidence suggests that tau itself may not be responsible for most of the damage.”
Partly supportedDavid M. Holtzman led the study.Latest Science News -- ScienceDaily: “David M. Holtzman, MD, senior author of the study”
SupportedHoltzman said, “In tauopathies, including Alzheimer's disease, there's no treatment right now that actually decreases neurodegeneration.”Latest Science News -- ScienceDaily: ““In tauopathies, including Alzheimer's disease, there's no treatment right now that actually decreases neurodegeneration,” said David M. Holtzman, MD, senior author of the study”
SupportedThe researchers had previously found that T cells enter mouse brains with abnormal tau and contribute to neurodegeneration.Latest Science News -- ScienceDaily: “In a 2023 study published in Nature, the researchers discovered that T cells enter the brains of mice with abnormal tau accumulation, concentrating in regions containing the most tau and contributing to neurodegeneration.”
SupportedThe study identified the CXCL10-CXCR3 pathway as guiding T cells into the brain.Latest Science News -- ScienceDaily: “This relationship suggested that the CXCL10 and CXCR3 pathway might be responsible for guiding harmful T cells into the brain.”
SupportedThe antibody did not need to enter the brain tissue to be effective.Latest Science News -- ScienceDaily: “The antibody reached the boundary of the brain but did not enter the brain tissue itself. This suggests that it may be possible to reduce neurodegeneration by targeting immune activity from outside the brain.”
SupportedHoltzman said the study showed for the first time in an animal model that tauopathies respond to a specific T-cell therapy.Latest Science News -- ScienceDaily: ““Tauopathies aren't thought of as autoimmune disorders, so they haven't been treated the same way, but this study shows for the first time in an animal model that these diseases respond to a specific T-cell therapy,” said Holtzman”