LY6E, the immunoprotein prevents coronaviruses from causing an infection, said new study. The protein enhances the infectivity of influenza viruses
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Strengthening influenza viruses, impairing corona viruses
Funded by a Marie Curie Individual Fellowship of the European Union, Stephanie Pfänder, who was then working at the Institute of Virology and Immunology in Switzerland, visited Charles Rice's lab at Rockefeller University in New York in 2017, in order to identify genes that prevent coronavirus infections. "This led to the discovery that LY6E has the opposite effect on coronaviruses compared to influenza viruses," explains the researcher. Further investigations showed that the protein exerted this inhibitory effect on all analysed coronaviruses, including the pathogens causing Sars and Mers as well as Sars-Cov-2 which causes Covid-19.
Viruses unable to fuse
Tests with different cell cultures showed that LY6E affects the ability of the virus to fuse with the host cells. "If the virus is unable to fuse with these cells, it can't cause infection," explains corresponding author Professor Volker Thiel from the University of Bern.
The validation in an animal model succeeded thanks to a collaboration with the laboratory of John Schoggins at the Southwestern Medical Center of the University of Texas. The experiments conducted there led to the discovery that the mouse variant of the protein called Ly6e is crucial for the protection of immune cells against infections. In the absence of Ly6e, immune cells such as dendritic cells and B-cells become more susceptible to infection and their numbers decrease dramatically. Mice lacking Ly6e in immune cells are highly susceptible to a normally non-lethal mouse coronavirus and succumb to infection.
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The researchers point out that the mouse coronavirus used in the experiment differs significantly from the pathogen causing the current Covid-19 outbreak - for example, it causes hepatisis rather than respiratory disease. Nevertheless, it is widely accepted as a model for understanding the basic concepts of coronavirus replication and immune responses in a living animal.
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Source-Eurekalert