Researchers at the University of Toronto have made a significant discovery. They identified a new RNA virus, Apocryptovirus odysseus, cohabiting with the human parasite Toxoplasma gondii. This virus, along with 18 similar ones, was unearthed through a comprehensive computer analysis of human neuron data.
The virus is associated with severe inflammation in individuals infected with Toxoplasma gondii, hinting at its potential to exacerbate toxoplasmosis. This finding could have profound implications in the fields of virology and parasitology.
Researchers found A. Odysseus in human neurons using the Serratus platform, which searches through over 150,000 RNA viruses. Serratus detects RNA viruses by identifying an enzyme called RNA-dependent RNA polymerase, which helps the virus replicate and spread.
T. gondii infections often go unnoticed, but toxoplasmosis is essential to study due to its widespread nature and impact on pregnant women and the immunocompromised. This is the first time a virus has been linked to toxoplasmosis. The newly discovered A. Odysseus virus is found in two highly virulent strains of T. gondii, RUB and COUGAR.
RUB, found in French Guinea, causes severe fever and organ failure. In contrast, COUGAR, found in British Columbia, is linked to ocular toxoplasmosis, a leading cause of infectious blindness. These strains were found in different locations, showing their broad impact.
Toxoplasmosis symptoms can worsen due to an overactive immune response triggered by the parasite’s virus. The 19 RNA viruses found are strong indicators of parasitic infection. A. Odysseus virus could help identify severe toxoplasmosis.
Artem Babaian, principal investigator on the study and assistant professor of molecular genetics at the Donnelly Centre and the Temerty Faculty of Medicine, said that “zoonotic viruses that infect other living things in our environment to reach us are expected to cause the majority of emerging infectious diseases in humans. This study underscores the importance of looking beyond the viruses that infect humans directly into the extended virome.”
Journal reference:
- Purav Gupta, Aiden Hiller, et al., A parasite odyssey: An RNA virus concealed in Toxoplasma gondii. Virus Evolution. DOI: 10.1093/ve/veae040.