Link Between Alzheimer’s Disease Pathologies and Herpes Virus

The tau protein is well known for its role in Alzheimer’s disease, where these proteins undergo modifications and accumulate inside neurons. This causes toxic effects inside the cell, leading to neuronal death and cognitive decline.

However, tau proteins are actually a normal part of the brain and can protect the brain from invading viruses. Normally, they bind the virus and inhibit them. A recent study finds that this is what happens in herpes simplex virus infection and explores how this may relate to Alzheimer’s disease. 

This study found that proteins from the herpes virus could be found in the brain in all stages of Alzheimer’s disease.

The presence of these proteins correlated with the presence of a highly modified version of tau and with Alzheimer’s severity. In organoid models (i.e. mini models of human brains), the study found that the herpes virus could affect the levels of modifications on the tau protein. These modified tau proteins reduced herpes virus protein levels and decreased post-infection neuronal death. It’s possible these modified tau proteins act as an innate immune response in Alzheimer’s disease.

This study highlights the complicated and interconnected nature of infections, immune responses, and neurodegeneration.

Citation:

Hyde et al. (2025). Anti-herpetic tau preserves neurons via the cGAS-STING-TBK1 pathway in Alzheimer’s disease. Cell Reports. https://doi.org/10.1016/j.celrep.2024.115109