Featured Research

from universities, journals, and other organizations

Slippery Salmonella: Proteomics Exposes An Infectious Agent Of Deception

Date:
October 4, 2006
Source:
Pacific Northwest National Laboratory
Summary:
How Salmonella escapes detection by macrophages, turning predator cells to prey complicit in promoting infection, has seemed impossibly complicated, a needle-in-a-haystack proposition involving thousands of proteins, the building blocks that carry out cells' vital functions. Now, applying the high-volume sorting and analytical power of proteomics -- a detailed survey of microbial proteins present in the 24 hours that follow mouse-macrophage infection -- a team from Pacific Northwest National Laboratory has turned up a suspect protein.

PNNL scientists have identified a protein in Salmonella bacteria that enables it to infect immune cells called macrophages. Seen here: Salmonella, isolated from infected macrophrages (mildly color-enhanced).
Credit: Photo credit: Pacific Northwest National Laboratory

Salmonella bacteria, infamous for food poisoning that kills hundreds of thousands worldwide, infect by stealth. They slip unnoticed into and multiply inside macrophages, the very immune system cells the body relies on to seek and destroy invading microbes.

Related Articles


Just how Salmonella escapes detection by macrophages, turning predator cells to prey complicit in promoting infection, has seemed impossibly complicated, a needle-in-a-haystack proposition involving thousands of proteins, the building blocks that carry out cells' vital functions.

Applying the high-volume sorting and analytical power of proteomics--a detailed survey of microbial proteins present in the 24 hours that follow mouse-macrophage infection--a team led by Liang Shi of the Department of Energy's Pacific Northwest National Laboratory has turned up a suspect protein.

The discovery of the protein, dubbed STM3117, is detailed today (Sept. 29) in The Journal of Biological Chemistry. Knocking out the gene that codes for STM3117, the researchers subsequently crippled the microbe's ability to multiply inside macrophages. Shi and colleagues say the protein and two closely related proteins discovered in the study are similar in genetic sequence to those known to make and modify chemicals in the microbe's cell wall called peptidoglycan.

Drug and vaccine designers armed with this mouse-model information can target chemicals or immune responses that disrupt peptidoglycan synthesis and other processes linked to Salmonella's colonization of macrophages in humans, said Joshua Adkins, a co-author on Shi's paper and lead author of a related study in Molecular & Cellular Proteomics last month. A quick identification of these proteins, Adkins added, could help physicians assess the virulence of a given strain.

The candidate proteins were winnowed from among 315 possibilities that emerged through a combination of techniques, culminating in measurements by Fourier-transform mass spectrometry, or FT-MS. A suite of FT-MS instruments customized by co-author and PNNL-based Battelle Fellow Richard D. Smith enabled the team to rapidly separate and identify many proteins at once even as macrophages were being infected.

Most of the initial candidates were designated "house-keeping" proteins, or those whose numbers relative to other proteins remained more or less constant during the course of infection. But 39 proteins shot up in number during bacterial colonization of macrophages, and of those, a handful or so--including STM3117--responded specifically to a macrophage protein associated with resistance to microbial infection. A standard assay called Western blot confirmed the abundance increases of that small group of proteins during infection.

The work was funded by PNNL and the National Institutes of Health's National Institute of Allergy and Infectious Diseases, and much of the work was performed at the PNNL-based W.R. Wiley Environmental Molecular Sciences Laboratory.


Story Source:

The above story is based on materials provided by Pacific Northwest National Laboratory. Note: Materials may be edited for content and length.


Cite This Page:

Pacific Northwest National Laboratory. "Slippery Salmonella: Proteomics Exposes An Infectious Agent Of Deception." ScienceDaily. ScienceDaily, 4 October 2006. <www.sciencedaily.com/releases/2006/09/060929093337.htm>.
Pacific Northwest National Laboratory. (2006, October 4). Slippery Salmonella: Proteomics Exposes An Infectious Agent Of Deception. ScienceDaily. Retrieved January 25, 2015 from www.sciencedaily.com/releases/2006/09/060929093337.htm
Pacific Northwest National Laboratory. "Slippery Salmonella: Proteomics Exposes An Infectious Agent Of Deception." ScienceDaily. www.sciencedaily.com/releases/2006/09/060929093337.htm (accessed January 25, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Sunday, January 25, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Florida Might Legalize Black Bear Hunting

Florida Might Legalize Black Bear Hunting

Newsy (Jan. 24, 2015) A string of black bear attacks has Florida officials considering lifting the ban on hunting the animals to control their population. Video provided by Newsy
Powered by NewsLook.com
Ebola Killing Large Portion Of Ape Population

Ebola Killing Large Portion Of Ape Population

Newsy (Jan. 23, 2015) Experts estimate Ebola has wiped out one-third of the world&apos;s gorillas and chimpanzees. Video provided by Newsy
Powered by NewsLook.com
Controversy Shrouds Captive Killer Whale in Miami

Controversy Shrouds Captive Killer Whale in Miami

Reuters - Light News Video Online (Jan. 23, 2015) Activists hope the National Oceanic and Atmospheric Agency (NOAA) will label killer whales endangered, allowing lawyers to sue a Miami aquarium to release an orca into the wild after 44 years. Jillian Kitchener reports. Video provided by Reuters
Powered by NewsLook.com
‘Healthy’ Foods That Surprisingly Pack on Pounds

‘Healthy’ Foods That Surprisingly Pack on Pounds

Buzz60 (Jan. 23, 2015) Some &apos;healthy&apos; foods are actually fattening. Fitness and nutrition expert John Basedow (@JohnBasedow) shines a light on the sneaky foods like nuts, seeds, granola, trail mix, avocados, guacamole, olive oil, peanut butter, fruit juices and salads that are good for you...but not so much for your waistline. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins