Sense and respond: investigating molecular mechanisms regulating Cryptococcus neoformans titan cell formation in response to bacterial triggers

Microscopic fungi are an under-appreciated cause of infection and death in patients worldwide. It is estimated that 1.5 million people die from fungal infections each year, which is comparable to the number of deaths from malaria. One of the most important fungi is Cryptococcus neoformans, which grows in the lung and escapes our immune defences, infecting the brain and causing meningitis. One way that Cryptococcus escapes immune cells is by extreme changes in cell size. So-called titan cells are much larger than immune cells and can survive immune attack, making them important to treatment strategies. But how these cells form is largely unknown.

I showed that titan cells form when Cryptococcus interacts with bacteria that normally grow in our lungs as part of our healthy microbiome. My research will address how bacteria trigger Cryptococcus to make titan cells, how Cryptococcus detects the presence of bacteria in its environment, and how Cryptococcus changes size to cause disease.

My findings will be used during the development of treatment strategies for fungal infections.