Blood Vessels and Immune Cells in the Brain: Dual Roles in Protection and Disease Risk

The health of the brain relies on more than just neurons; it depends on a sophisticated network of blood vessels and immune cells that serve as its guardians. This network maintains the blood-brain barrier, controls what passes into the brain, and clears waste products. Recent research by scientists at Gladstone Institutes and UCSF has uncovered that these vital cells not only protect the brain but may also contribute to the development of diseases such as Alzheimer's and stroke.

Using an innovative technique called MultiVINE-seq, the team isolated vascular and immune cells from postmortem human brain tissue. This approach enabled a detailed map of gene activity and chromatin accessibility—the 'dimmer switches' that regulate gene expression—in these cells. Analyzing 30 brain samples from individuals with and without neurological conditions, they found that many genetic variants associated with neurological diseases are active in blood vessel and immune cells rather than neurons.

One of the study’s key findings is that genetic risk factors influence these guardian cells differently depending on the disease. For instance, variants linked to stroke tend to weaken the structural integrity of blood vessels, increasing vulnerability to physical damage. In contrast, variants associated with Alzheimer’s disease often heighten immune activity, leading to overactive inflammation. Notably, a common variant near the PTK2B gene was found to enhance immune cell activation, suggesting that immune overdrive may be a contributing factor in Alzheimer’s pathology.

This research highlights the importance of the brain’s vascular and immune boundary cells as potential therapeutic targets. Their strategic location at the interface between the brain and the body makes them sensitive to lifestyle and environmental factors, offering a promising avenue for interventions that bolster brain defenses without crossing the blood-brain barrier. Ultimately, these findings shift the focus from neurons to the broader cellular landscape that governs brain health and disease.

Source: https://medicalxpress.com/news/2025-07-blood-vessels-immune-cells-brain.html