Newly Discovered Protein Facilitates TBE Virus Entry into Brain Cells

Researchers from the Karolinska Institutet and international partners have identified a key protein on cell surfaces that is essential for the tick-borne encephalitis (TBE) virus to infect human cells. The study, published in Nature, reveals that the protein LRP8 acts as a critical receptor enabling the virus to cross cellular barriers and invade brain cells. This breakthrough was achieved by exposing a vast library of genetically modified cells to the virus, pinpointing LRP8 as the crucial factor; cells lacking this protein survived infection, indicating its vital role. LRP8 is highly expressed in brain tissue, making it especially relevant to the neurological impacts of TBE.

The virus is predominantly transmitted through tick bites, which can lead to severe neurological diseases. Its prevalence is increasing across Europe and Asia, paralleling the rise in tick populations. Despite the availability of a vaccine, there are no targeted treatments for individuals already infected. As a biosafety level 4 pathogen, TBE requires strict laboratory protocols.

The study demonstrated that the TBE virus’s surface protein specifically binds to LRP8, exploiting this receptor to gain entry into cells—particularly neurons in the brain. Understanding this mechanism opens new avenues for developing antiviral drugs that block this interaction, potentially preventing infection or reducing its severity. Notably, this research marks the first identification of a direct host cell receptor for a flavivirus, a family of viruses that includes yellow fever, dengue, and Japanese encephalitis, which are typically transmitted by mosquitoes or ticks.

Future research aims to understand how LRP8 facilitates the virus’s pathogenic effects within the brain’s neuronal network. The discovery offers hope for innovative therapies that can inhibit the initial stages of TBE virus infection, significantly impacting public health in endemic areas.

Source: https://medicalxpress.com/news/2025-09-key-protein-borne-encephalitis-revealed.html