An international team of researchers has identified the specific protein that tick-borne encephalitis virus (TBEV) uses to infect human cells, marking a significant breakthrough in understanding how the virus causes neurological disease. The study, co-led by scientists from Albert Einstein College of Medicine, Karolinska Institutet, and the United States Army Medical Research Institute of Infectious Diseases (USAMRIID), was published on September 24, 2025 in the journal Nature. This discovery represents the first time researchers have conclusively identified an essential host-cell protein receptor for any flavivirus.

TBEV belongs to the flavivirus genus, which includes other serious mosquito- and tick-borne pathogens such as dengue virus, yellow fever virus, Zika virus, and Japanese encephalitis virus. Until now, scientists had been unable to identify the critical protein receptors that these viruses use to enter human cells. "By conclusively demonstrating that TBEV requires a critical protein receptor to infect human cells, we open the field to discovering receptors for other flaviviruses and devising therapies for the devastating infections they cause," said study co-leader Kartik Chandran, Ph.D., professor of microbiology & immunology at Einstein.

The research team identified LRP8 as the crucial protein that acts as a receptor for TBEV infection. Using a sophisticated screening method, researchers exposed thousands of cell variants with different genes removed to TBEV and found that cells lacking the LRP8 gene survived exposure. "LRP8 is a protein on the cell surface that is highly expressed in brain cells," explained Sara Gredmark Russ, Associate Professor of Infectious Diseases at Karolinska Institutet, who led the study at KI. The protein essentially functions as a "door opener" for the virus to enter human cells.

This discovery has significant implications for developing new treatments for tick-borne encephalitis, a disease that currently has no specific antiviral therapies available despite the existence of a preventive vaccine. TBEV is transmitted through tick bites and can infect the brain and spinal cord, causing severe and sometimes life-threatening neurological disease. With the virus endemic throughout Northern, Central and Eastern Europe, and Central and East Asia, and cases expected to increase due to climate change and expanding tick habitats, this breakthrough provides a crucial foundation for future antiviral drug development.

Eskilstuna Municipality has filed an appeal against the Swedish Chemicals Agency's decision to grant Senior Material a permit to use methylene chloride in its production of separator film for electric vehicle batteries. The municipal board reached this decision on October 2nd, with the community building committee scheduled to address the matter during its meeting on October 3rd. The appeal represents a significant challenge to the regulatory approval process for industrial chemical use in Sweden.

The controversy centers on methylene chloride, also known as dichloromethane (DCM), a chlorinated solvent that has been nationally prohibited in Sweden since 1996 due to health risks for workers handling the substance. The chemical is classified as carcinogenic and capable of causing genetic changes, while also being harmful to aquatic organisms. Senior Material received an exemption from this ban for its planned production operations, marking a notable exception to Sweden's long-standing restrictions on the substance.

Public concern over the potential environmental impact has manifested in substantial community opposition. Hundreds of demonstrators gathered outside Senior Material's factory in the Svista industrial area on October 1st, expressing worries about future emissions of the chemical. The protest movement has gained momentum through social media campaigns and a petition that has collected over 130,000 signatures demanding the cessation of methylene chloride emissions.

Municipal officials cite multiple grounds for their appeal, particularly emphasizing the volume of methylene chloride approved—1,280 tons over a two-year period—which they describe as unreasonable given Sweden's phase-out objectives for the substance. Niklas Edmark, business director for Eskilstuna Municipality, stated that the approved quantity significantly exceeds what has been permitted in Sweden in recent years and conflicts with national sustainability goals. The municipality argues that the Chemicals Agency should have applied the precautionary principle more rigorously and expanded its assessment criteria given the scale of proposed use.