Adenoviruses have a linchpin protein that stabilizes their DNA until it reaches the infected cell’s nucleus. The protein then detaches from the viral genome, and the virus uncoats. Only then are the genes released into the nucleus, which is necessary for the production of new viruses. This process, discovered by researchers at the University of Zurich, is a key for effective functioning of various Covid-19 vaccines.
Adenoviruses cause respiratory illnesses in humans and have been used as vectors in vaccination for many years, for example against MERS and Ebola virus. Several Covid-19 vaccines are based on replication-defective adenoviruses, including products from AstraZeneca, Johnson & Johnson, CanSino Biologics and Sputnik V. The vaccinated cells produce the SARS-CoV-2 spike protein on their surface, and thereby trigger a protective immune response in the human body.
Researchers are exploiting a key feature of adenoviruses, namely their ability to infect human cells and transfer foreign DNA into the nucleus of these cells. A new study led by Urs Greber, professor at the Department of Molecular Life Sciences at the University of Zurich (UZH), now shows that this process evolved a sophisticated mechanism.