US researchers are conducting a study to understand the mechanism by which cells grow and cancer develops, and they are using the bacterial pathogen Listeria Monocytogenes in their project.
The research team, which includes University of Central Florida Microbiology Professor Keith Ireton, had recently found that a Listeria protein called InlB induces internalisation and degradation of a human receptor known as Met, which has been implicated in the development of some cancers.
Ireton worked with Lisa A. Elferink of the University of Texas Medical Branch, who led the study study published in the Journal of Biological Chemistry this month. They found that the ability of InlB to induce Met internalisation and degradation requires a human protein called Cbl.
The researchers feel that the knowledge of how to control Cbl may lead to the development of drugs that induce the destruction of Met, and are useful in treating Met-related cancers.
'We found that Listeria actually 'provokes' human epithelial cells (cells lining the small intestine) into ingesting bacteria,' said Ireton, an expert on Listeria monocytogenes, a cause of food poisoning.
'When Listeria contacts an epithelial cell, the bacterium causes changes in the cell's 'cytoskeleton' that allow the cell to swallow up the bacterium. We discovered that a human protein called CrkII plays a critical role in stimulating internalisation of Listeria by somehow controlling the cytoskeleton,' adds the researcher, who explains the mechanism in this month's issue of the journal Cellular Microbiology.
Listeria is a potentially deadly pathogen, causing abortions in pregnant women and meningitis in those with compromised immune systems, resulting in about a 25 per cent mortality rate.
The findings are significant with a view to understanding and controlling the spread of bacteria that are a cause of potentially fatal food poisoning.
According to Ireton, the bacteria can live outside animal hosts, and its sources include dead plant matter, fruits and vegetables, unpasteurized diary products, and meats that have not been properly cooked.
Pregnant women and people with compromised immune systems are particularly susceptible.
Ireton suggests that contamination can be avoided by cooking all meats thoroughly, avoiding dairy products that are not pasteurised, and washing all fruits and vegetables thoroughly before consumption.