Immune Response, Not Virus, Linked to Neurological Damage in Viral Infections

McMaster University Researchers Challenge Traditional Beliefs, Offer New Therapeutic Insights

Hamilton, Canada, February 5, 2024 – In a groundbreaking discovery challenging conventional wisdom, researchers from McMaster University have identified that immune system responses, rather than the viruses themselves, are responsible for neurological damage associated with acute viral infections. The findings, published in Nature Communications, pinpoint a specific population of T cells, NKG2D+CD8+, as the instigators of neurological damage in infections such as Zika, COVID-19, and septic shock.

Key Revelations:

1. T Cells with a Twist: While investigating the connection between viral infections and neurological disorders, researchers observed T cells, specifically NKG2D+CD8+, exhibiting an atypical behavior. Instead of targeting infected cells, these cells displayed an aggressive response, causing collateral damage to healthy cells.
2. Beyond Zika: The study, initially focused on Zika virus, revealed that the identified T cells were not restricted to Zika infections but were implicated in other viral infections, including COVID-19 and septic shock.
3. Inflammatory Cytokines’ Role: The aggressive T cell response was linked to the overproduction of inflammatory proteins called cytokines. Excessive cytokine release led to non-specific activation of immune cells, resulting in collateral damage, particularly in the brain.
4. Target for Therapies: Recognizing the immune response as the key driver of neurological damage opens new avenues for therapeutic interventions. An antibody experiment by lead researcher Elizabeth Balint demonstrated promise in treating neurotoxicity in animal models, offering hope for potential human applications.
5. Potential Treatment: Balint’s ongoing work involves exploring treatment options targeting the identified immune response. An antibody that showed efficacy in animal models is already in clinical trials for various human applications.

Implications for Future Research:

The McMaster University study challenges established notions surrounding viral-induced neurological damage and presents a paradigm shift in understanding the role of the immune system in such conditions. The identification of specific T cell populations and their aggressive response provides a potential target for developing treatments that could mitigate collateral damage during viral infections.

As researchers delve into additional viruses, the ongoing work holds promise for advancing treatment options and improving outcomes for individuals facing neurological challenges resulting from acute viral infections. The findings pave the way for a more nuanced and targeted approach in the fight against viral-induced neurological diseases.

More information: Bystander activated CD8+ T cells mediate neuropathology during viral infection via antigen-independent cytotoxicity, Nature Communications (2024). DOI: 10.1038/s41467-023-44667-0