These faces staring back at you are no apparition. Despite their ghostly appearance, these are very real cell nuclei infected with Influenza A virus - the only influenza virus known to cause pandemics.
And the cells the virus is infecting? They're from a lung cancer cell line known as A549, which is a good place to observe how Influenza A virus replicates. Once the virus has got inside the host cells, its genome is able to travel into the nucleus through a special gateway called the nuclear pore complex.
Nikenza Viceconte, who worked in the Kosinski Group at EMBL Hamburg until March (now Head of Lab Processing at Centogene), was part of the team trying to understand that gateway and how the virus moves between the cell's nucleus and the rest of the cell, and ultimately other cells that it then infects. This research will help us to better understand the whole viral infection cycle. Using a confocal microscope, Nikenza managed to visualise the influenza A virus at the edge of a cell's nucleus. In these images, she has stained a viral protein (green) and a specific human protein (red) to see them more clearly. The dark areas inside the nucleus (nucleoli) probably indicate an absence of virus. And they also make a good spooky face.
Credit: Nikenza Viceconte/EMBL
