Nav: Home

Re-trafficking proteins to fight Salmonella infections

June 09, 2020

When humans get infected by pathogenic bacteria, the body's immune system tries to eliminate the intruders. One way of doing this is by launching an inflammatory response - a cascade of events that includes the expression of protective proteins, the activation of immune cells, and a process of controlled cell death when infected cells can't be saved.

Scientists including members of EMBL's Typas group, members of the group of EMBL alumnus Jeroen Krijgsveld at the German Cancer Research Center (DKFZ) in Heidelberg, and other collaborators have investigated how immune cells called macrophages respond to infection by the intracellular pathogen Salmonella enterica. The scientists applied a method recently developed in their labs to enrich, identify, and quantify all newly produced proteins from Salmonella-infected macrophages. They marked newly produced proteins with a specific chemical label and identified them using a technique called mass spectrometry, which allowed them to analyse the entire set of cellular proteins. Importantly, the scientists measured protein levels in macrophages at different infection stages and across different cell compartments. Their study, which is published in Nature Microbiology, shows that monitoring the dynamic changes in protein production and targeting can reveal new insights into the mechanisms by which cells respond to pathogens.

One of the unexpected findings of the study was that a well-known family of proteins called cathepsins move to a new location when cells get infected by Salmonella. Cathepsins are proteases - proteins that break down other proteins. They're normally kept inside small subcellular structures known as lysosomes and have previously been implicated in promoting cell death, although the mechanism or any link between the process and bacterial infection were unknown. The scientists have now discovered that Salmonella causes newly produced cathepsins to accumulate in the nuclei of infected cells. The protein-degrading activity of cathepsins in the nucleus is then required to initiate an inflammatory form of programmed cell death.

The new study shows the benefit of systematically following protein dynamics during infection, which can unravel new pathways and mechanisms the host uses to defend itself against pathogens.
-end-


European Molecular Biology Laboratory

Related Salmonella Articles:

Sneaky salmonella finds a backdoor into plants
Researchers have discovered that bacteria such as salmonella, E.coli and listeria have a backdoor to take advantage of humans' reliance on leafy greens for a healthy diet.
Re-trafficking proteins to fight Salmonella infections
New study demonstrates how monitoring all cellular proteins over time and space can improve our understanding of host-pathogen interactions.
Researchers find one-two punch may help fight against Salmonella
Researchers found that dephostatin does not kill Salmonella or stop it from growing.
Food scientists slice time off salmonella identification process
Researchers from Cornell University, the Mars Global Food Safety Center in Beijing, and the University of Georgia have developed a method for completing whole-genome sequencing to determine salmonella serotypes in just two hours and the whole identification process within eight hours.
The discovery of ancient Salmonella
Oldest reconstructed bacterial genomes link agriculture and herding with emergence of new disease.
The function of new microRNAs are identified in Salmonella and Shigella infections
The research, published in Nature Microbiology, could help the search for more effective medicine and delves deeper into understanding the role of microRNAs in gene expression.
Salmonella the most common cause of foodborne outbreaks in the European Union
Nearly one in three foodborne outbreaks in the EU in 2018 were caused by Salmonella.
The nature of salmonella is changing -- and it's meaner
Salmonella is acting up in Michigan, and it could be a model for what's happening in other states, according to a new Michigan State University study.
Salmonella -- how the body fights back
New research shows how our immune system fights back against Salmonella infection.
For salmonella detection, genomic tool emerges as a key
The world's food supply will become safer as the food industry shifts to high-resolution, whole-genome sequencing -- which examines the full DNA of a given organism all at once.
More Salmonella News and Salmonella Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Warped Reality
False information on the internet makes it harder and harder to know what's true, and the consequences have been devastating. This hour, TED speakers explore ideas around technology and deception. Guests include law professor Danielle Citron, journalist Andrew Marantz, and computer scientist Joy Buolamwini.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at Radiolab.org/donate.     You can read The Transition Integrity Project's report here.