Scientists Uncover Microglia’s Role as Project Managers of Brain Immunity

Infections in the brain can have severe and often fatal consequences, owing to the unique manner in which the immune system operates within this vital organ. A recent study conducted by researchers at TWINCORE, the Center for Experimental and Clinical Infection Research in Hanover, has shed light on the crucial signaling pathways that facilitate communication among immune cells in the brain during viral infections. Published in the Journal of Neuroinflammation, the research highlights how microglia, the brain’s resident immune cells, act as central coordinators in the brain’s defense against viruses.

The immune response in the brain involves complex interactions where infected cells are identified and eliminated to prevent the spread of viruses like vesicular stomatitis virus (VSV). Microglia, often considered the project managers of brain immunity, recognize these infections and communicate with T cells to mount a coordinated defense.

Dr. Andreas Pavlou from TWINCORE explains that microglia's role is mediated through specific signaling pathways. The team investigated the importance of MAVS—mitochondrial antiviral-signaling protein—in this process. Using mouse models with targeted deletion of MAVS in different cell types, the researchers discovered that removing MAVS from microglia significantly impeded immune coordination, leading to rapid viral spread within the brain. In contrast, deleting MAVS from neurons or astrocytes had little effect.

The findings revealed that microglia with functional MAVS receptors maintain proper signaling surface receptors and metabolic activity in T cells, enabling an effective immune response. When MAVS was absent, microglia failed in their coordinator role, resulting in disrupted communication with T cells and weakened immunity.

Professor Ulrich Kalinke emphasized that understanding MAVS’s role offers potential for developing new therapeutic strategies to combat brain infections more effectively, potentially improving patient outcomes in the future. Overall, this study emphasizes the microglia’s critical function as immune system project managers in the brain, orchestrating protective responses against viral threats.

Source: https://medicalxpress.com/news/2025-07-immune-defense-brain.html