Taking an Acid Bath: Virus Entry into Cells and the Action of Anti-Viral Drugs
Gary Whittaker

Viruses must replicate inside living cells in order to survive. They must gain access to the cell’s interior and at the same time activate themselves for replication. Influenza (flu) virus first binds to a receptor on the surface of cells and then is taken up into small vesicles. As the virus enters the interior of the cell, the vesicles become progressively acidic, due to a drop in pH. This acidification (or acid bath) is the trigger that the virus needs to break out of the vesicle and enter the cell nucleus, where virus replication takes place. An anti-viral drug, used to prevent influenza infection in humans, prevents the virus from taking its acid bath and blocks infection.

During this exploration, students will observe the techniques used in the lab to grow cells and infect them with influenza virus. Infected cells will be treated with anti-viral drugs and stained with antibodies to viral proteins. Students will then perform fluorescence microscopy to see the progress of the infection and the blockage occurring in the presence of drugs.