The influenza A virus does not just invade human cells. It dismantles tiny structures inside the nucleus and releases proteins that may help the virus copy itself. That finding comes from a new molecular map built by researchers at EMBL Hamburg and the Leibniz Research Institute for Molecular Pharmacology (FMP) in Germany.
A first look inside intact infected cells
The team developed a customized workflow to observe protein interactions directly inside living cells. Earlier studies often required breaking cells open before measuring those contacts. That method can distort what was actually happening. Once internal compartments are destroyed, proteins that were separated inside the cell may mix in the lab, while weak or temporary connections can vanish. The new approach avoids that problem. It is the first large scale map of direct contacts between influenza proteins and human proteins inside intact infected cells. The detail was precise enough for researchers to model how the proteins may fit together.
What the virus does to the nucleus
Influenza A enters a cell and releases RNA that carries instructions for making viral proteins. Those proteins spread through the host cell and redirect its molecular systems. The new map shows that the virus dissolves specific structures inside the nucleus. That releases proteins the virus may use to fuel its own replication and potentially weaken the cell's antiviral defenses. The study focused on a snapshot of one moment during infection. The researchers said the method opens the door to studying flu host interactions across the entire infection cycle.
Seasonal influenza causes 3 to 5 million cases of severe illness worldwide each year and is linked to as many as 650,000 deaths. Influenza A has driven multiple pandemics, including the 1918 Spanish Flu. A clearer view of how the virus hijacks cells could help scientists develop more effective vaccines and antiviral drugs. The detailed map may also help researchers study dangerous flu strains such as H5N1.
