My name is Katherine Pline and I’m a third year PhD student in the Johnston Lab in Sheffield. I am interested in how invading pathogens and infections interact with the human immune system. I work on an infectious agent called Cryptococcus neoformans, a yeast which is inhaled into the lungs and can infect the brain.
5 day old zebrafish larva infected with C. neoformans (Kn99gfp - green)
When an infection occurs, human white blood cells are called to the scene to combat the infection. Like most events in life there is more than one way to go, and more than one possible outcome. If the immune system wins, the infection is defeated. If the immune system fails, the infection spreads. In C. neoformans infection, white blood cells called macrophages can either eat and kill the yeast, or can carry it to distant parts of the body and infect the brain. The direction the macrophage goes in depends on what happened to it before – its backstory.
We have used zebrafish infections to watch how the infection progresses in each fish through time and, with help from the brilliant James Bradford and Dr Rhoda Hawkins, have used this to make a computational model of what happens in infection. This research has helped us to understand how the immune system interacts with the pathogen C. neoformans, how the yeast uses our macrophages to spread, and how our body mounts defences to stop it. Like the journeys we all face, infection here can lead to a happy ending, or can end in disaster and disease. While each person who faces a challenge, an infection, is unique, we must all fight to be victorious, and learn as much as we can in the process.
Human macrophages (MDMs) infected with C. neoformans (Kn99gfp - green)