Study Identifies Powerful Immune‑Evasion Enzyme in Pacific Coast Tick Nairovirus
High‑resolution structures and computational models link a highly active OTU protease to a nairovirus found in a human‑biting Pacific Coast tick and point to targeted biosurveillance needs.
Overview
- A peer‑reviewed ACS Infectious Diseases paper published in July 2026 shows that nairoviruses use OTU proteases to remove ubiquitin and ISG15, two small protein tags that trigger human antiviral responses.
- Researchers isolated OTU enzymes from four emerging nairoviruses and found varied ability to strip those immune tags, establishing OTU activity as a key molecular measure of viral immune evasion.
- The OTU from Pacific Coast Tick nairovirus (PCTNV) displayed the strongest deubiquitinating and deISGylating activity in laboratory tests, suggesting enhanced capacity to blunt human immune signaling.
- The team solved several OTU crystal structures and used those details to train early computational models that aim to predict which nairoviruses pose greater human risk and guide surveillance efforts.
- PCTNV has been detected in Dermacentor occidentalis ticks in Mendocino, California, no human infections are confirmed, and the authors recommend focused tick‑species testing and molecular monitoring rather than broad public alarm.