Plundering the fungal factories of ants for new drugs
In the search for powerful anticancer and antifungal drugs, scientists look somewhere new -- fungus-farming ants.
In the world of the leaf-cutter ants in the Atlantic Forest of Brazil, there are good fungi and bad fungi.
The ants bring partially digested leaves back to their nests to nourish a crop of the good fungi, which they use to feed their queen and their fellow ants. However, this crop of white, beneficial fungus is under constant threat from a destructive parasitic fungus called Escovopsis. To combat this nefarious invader, the ants have formed an evolutionary partnership with a bacteria called Pseudonocardia, which basically kicks Escovopsis' butt while leaving the fungal food supply of the ants intact.
Now, a team of scientists from the US and Brazil is embarking on a study of Pseudonocardia and other bacteria in the hopes of finding the key to creating drugs that will combat cancer and dangerous fungal infections in humans.
"I'm very excited. I think this project has a good chance of success, and I think it aligns ecology and drug discovery in a way that we haven't tried before," said Jon Clardy, a professor of biological chemistry and molecular pharmacology at Harvard Medical School, in a statement. Clardy will co-lead the project with medicinal chemist Mônica Pupo of the University of São Paulo.
This is the first time anyone will be searching for beneficial products in fungus-farming ant ecosystems, according to the researchers.
As opposed to the superficial fungal infections that invade our skin and nails, those that take root inside our bodies can be deadly. "Worldwide, more people die of invasive fungal diseases than die of malaria or tuberculosis," Clardy said. "What's scary is it's not widely appreciated how dangerous these diseases are because the incidence is quite low, but the mortality is typically very high."
The hope is that by studying the compounds produced by the bacteria that protect the fungus factories of Brazil's jungle ants, the researchers will be able to engineer a compound that protects our bodies from invasive fungi as well. They will be studying multiple types of ant colonies (as well as the homes of other fungus-nurturing critters like termites and wasps) and will cultivate the bacteria they find, screening approximately 500 different strains per year.
They're off to a good start with Pseudonocardia. This fungus fighter "belongs to a group of actinobacteria that has already provided most of the world's antibiotics as well as antifungals, antivirals, anticlotting drugs, and more," according to the HMS News article.
Because chemotherapy drugs work similarly to antifungals -- killing faster-growing tumor cells while hopefully leaving slower-growing, healthy cells to flourish -- there is hope that the research could also lead to new cancer-fighting compounds.
The new research project has received a $5,154,376 grant over five years from the National Institutes of Health and the State of São Paulo Research Foundation. In recent related work, the team "cultured fewer than 200 kinds of insect-associated actinobacteria and found 20 never-before-seen natural products," the statement said. A lot of potential lurks in those fungus farms.