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Scientists describe the relationship between a virus and the infected host organism.

  • Science Park
  • September 30th, 2024
Santiago F. Elena, Victoria García Castiglioni and María José Olmo Uceda, en su labporatorio del I2SysBio
Santiago F. Elena, Victoria García Castiglioni and María José Olmo Uceda, en su laboratorio del I2SysBio. Créditos: CSIC

The Institute for Integrative Systems Biology (I2SysBio, UV-CSIC) describes a viral infection process of an organism, from birth to sexual maturity, with the highest temporal resolution achieved to date. The work, published in ‘Science Advances’, opens the door to the search for new antiviral therapeutic targets based on the mechanisms of response to chronic infection.

A team from the Institute of Integrative Systems Biology (I2SysBio, UV-CSIC) has described the response of a living organism, from birth to sexual maturity, to chronic virus infection. Using different techniques, the work analyses how the nematode Caenorhabditis elegans-a worm widely used as an experimental model- controls the infection of the Orsay virus from its birth to its reproductive phase, with the highest temporal resolution so far in a complete organism.

The study describes the accumulation and localisation of the virus in the tissues of the host organism, and analyses its genetic response during infection. To this end, the transcriptome - a set of RNA molecules - has been analysed by comparing the expression of genes from infected and non-infected animals. Caenorhabditis elegans is commonly used in research because of its genetic similarity to humans, with more than 80% of its proteins being similar. Its natural parasite, the Orsay virus, is an RNA virus first described in 2011 and similar to other human pathogens such as those causing avian influenza or COVID-19.

¨The use of a complete organism, while adding complexity to the results, also gives us a more realistic account of what happens in natural situations¨, commented Victoria García Castiglioni and María José Olmo Uceda, CSIC researchers at I2SysBio and authors of the study.

Through a multidisciplinary approach, using techniques from virology, genetics, transcriptomics and molecular, computational and developmental biology, they have managed to describe this process of chronic infection with an unprecedented level of detail and temporal resolution. Thus, for example, they have classified the response genes to viral infection into different basic profiles: early response genes that are activated just after infection; genes whose profile correlates with the amount of virus throughout the development of the organism; or late response genes that are only activated in the last phase of infection.

Furthermore, they have made a temporal description of the virus cycle; they have identified the genes that the virus uses for its benefit and those that the animal uses as a defence, and they have marked the specific response genes to viral infection, in contrast to non-specific responses to infection with other pathogens.

Viruses that cause severe acute illnesses are the most studied, due to their socio-economic impact. However, we live with chronic viruses and persistent infections of these viruses accompany us throughout our lives,’ says Santiago F. Elena, a CSIC researcher who heads the Evolutionary and Systems Virology group at I2SysBio, which carried out the study. ‘This is the case we have studied, where the first infection of the virus does not cause severe acute symptoms and shows an example of a successful defence strategy that, without eliminating the virus from the organism, is capable of controlling it.

The results just published in the journal Science Advances ‘open the door to the search for new antiviral therapeutic targets with future clinical applications’, says the I2SysBio researcher.

Reference

 Castiglioni, V.G., Olmo-Uceda, M.J., Villena-Giménez, A., Muñoz-Sánchez, J.C., Legarda, E.C., Elena, S.F. (2024) Story of an infection: viral dynamics and host responses in the Caenorhabditis elegans-Orsay virus pathosystem Science Advances. DOI: 10.1126/sciadv.adn5945