Researchers at the University of Queensland have discovered a way to fight Listeria infections, which can cause serious illness in pregnant women and people with weakened immune systems.
During the study, the researchers discovered a way to prevent Listeria from making the proteins that allow the bacteria to survive and multiply in immune cells.
Professor Antje Blumenthal of the UQ Diamantina Institute said the use of a small drug-like inhibitor improved their understanding of the Achilles’ heel of Listeria.
“Listeria is found in soil and sometimes in raw foods. Once ingested, it can hide from the immune system and multiply inside immune cells,” Professor Blumenthal said.
“Instead of killing bacteria, immune cells are used by bacteria to multiply and are often killed by Listeria growing inside them.
“Our study showed that the bacteria could be killed with a small drug-like inhibitor that targets the ‘master regulator’ of proteins that help Listeria grow in immune cells. The inhibitor helped immune cells survive the infection and kill the bacteria.
So far, studies of the “master regulator” – which controls the critical proteins that make Listeria virulent – have mostly been based on engineered bacteria or mutated versions of these proteins.
“By using a drug-like inhibitor, we were able to use molecular imaging and infection studies to better understand what happens to Listeria when the bacteria can’t grow effectively inside immune cells and hide immune defense mechanisms,” Professor Blumenthal said.
“We hope that our discovery, together with recent research into the molecular structure and functions of master proteins, can guide the development of inhibitors and new drugs to treat Listeria infection.
Listeria infection does not cause illness in most people, but can be fatal for immunocompromised people and is also a major health problem during pregnancy and can lead to miscarriage, stillbirth and premature birth.
“Our findings could also inform the design of inhibitors against related proteins found in different bacteria,” said Professor Blumenthal.
The study was published in the journal PLOS pathogens (DO I: 10.1371/log.ppat.1010166).
This study, led by researchers at the UQ Diamantina Institute, included collaborations with Umeå University, Sweden; UQ School of Chemistry and Molecular Biosciences; Australian Center for Infectious Disease Research; Institute of Molecular Bioscience; Institute for Matter Research; Telethon Kids Institute, University of Western Australia; Monash University; University of Melbourne at the Peter Doherty Institute for Infection and Immunity and Hudson Institute of Medical Research.