Associate Professor Kirsten Nielsen.
Associate Professor Kirsten Nielsen.
14 April 2016

Cryptococcus is so forsaken by research that it doesn’t even make the neglected diseases list – but the deadly fungal pathogen has lured an American scientist all the way to The University of Queensland.

Associate Professor Kirsten Nielsen will spend a year at UQ’s Australian Infectious Diseases Research Centre on a Fulbright Senior Scholarship, working to understand Cryptococcus.

“It doesn’t have a catchy name like Zika or Ebola, so it’s not getting the attention it deserves,” Associate Professor Nielsen said.

Cryptococcus is a fungal pathogen that kills close to half a million people each year, particularly in southern Africa.

Dr Nielsen’s goal is to understand how the pathogen causes disease in order to determine ways to treat it.

“Crytococcus produces unique cells called ‘titan’ cells that allow it to cause disease, but we’re not sure what these titan cells do during the infection,” she said.

“What we do know is these cells are allowing the organism to adapt to the host very fast by jump-starting evolution.

“Where natural selection would take many generations to produce an organism adapted to the host environment, the titan cells allow Cryptococcus to adapt to humans in just one generation.”

And she estimates that most of the world’s population have been exposed to the pathogen.

“Every breath you take, you inhale 100 fungal spores yet you almost never see fungal infections in healthy people.

“Statistically speaking, most of the world is exposed to Cryptococcus by the age of five and it’s just sitting there latent, controlled by the immune system.”

When immunity is compromised, such as from AIDS or an organ transplant, Cryptococcus is at its most destructive.

“In southern Africa particularly, the mortality rate can reach 70 per cent. In Western countries with strong healthcare, it kills one in five who contract the disease.

The disease has drawn Dr Nielsen out of her medical laboratory and across the world to view a particular molecule important for producing titan cells from the perspective of a structural biologist.

“I usually think a lot about disease in patients, but here I’m thinking much more on a basic biological level and integrating chemistry and structural biology into our studies,” she said.

“By performing a structural analysis of the molecule, we gain better insight into how this molecule is able to generate titan cells, and hopefully develop new drugs that target this molecule.

“The ultimate goal is to stop the production of these titan cells and stop the evolutionary process that allows Crypto to cause disease.”

She is hosted at UQ by Associate Professor James Frasier in the Fungal Pathogenesis Laboratory, who she met 10 years ago while studying in America.

“James and I have actually known each other scientifically for over 10 years. We trained together in the US during our postdoctoral studies.

“James’ research interests differ from mine and so when my program started heading in a direction that could bring in his expertise, I wanted to tap into his skill set, and that of his collaborators, to answer questions that I couldn’t answer on my own,” Dr Nielsen said.

“I think my great hope this year is to take some of the strengths from the School of Chemistry and Molecular Biosciences and drug development and apply these to my system, expand on those studies and incorporate them into my research program.”

Those interactions are what make a successful sabbatical, she said.

This particular sabbatical was two years in the planning, and required moving her husband Joseph Knight and 12-year-old daughter to Brisbane for a year.

Her husband is on sabbatical in the UQ School of Geography and Environmental Management.

And it’s been going great so far, with the whole family scuba-diving at North Stradbroke, Moreton Bay and Gold Coast, and joining UQ’s Unidive club, Associate Professor Nielsen said.

“Minnesota has snow on the ground six months of the year so Australia is very different.

“We love it. We love the country and love the friendly and outgoing personalities who have made it very easy to join the community.”