Featured Research

from universities, journals, and other organizations

Golden staph paralyzes immune defenses

Date:
November 25, 2013
Source:
Centenary Institute
Summary:
When golden staph enters our skin it can identify the key immune cells and 'nuke' our body's immune response. Now we know how, thanks to an international research group.

This shows the depletion of macrophages (in green) after injection of S. aureus (orange-red material) into the skin. Normal skin is on the left; infected skin is on the right.
Credit: Centenary Institute/Nature Immunology

When golden staph enters our skin it can identify the key immune cells and 'nuke' our body's immune response.

Now we know how, thanks to an international research group led by dermatologists from the Centenary Institute and the University of Sydney.

Using state-of-the art microscopy techniques, the team identified the key immune cells that orchestrate the body's defenders against invading golden staph, and also how the bacteria can target and destroy these cells, circumventing the body's immune response.

Golden staph (Staphylococcus aureus) is the multi-drug resistant bacterium that is the scourge of hospitals.

The details of the study have been published today in Nature Immunology. It also involved researchers from The Univeristy of Sydney's School of Biological Sciences, Monash University, Singapore Immunology Network (A*STAR), and Harvard Medical School.

"Staphylococcus aureus kills many, many people around the world. In fact, more than tuberculosis and AIDS put together. And the skin is its primary entry point into the body, so it important to understand what happens in the skin," says Professor Wolfgang Weninger, Head of the Immune Imaging Research Program at Centenary and coordinator of the study.

Using techniques they have developed over the past decade, the research team was able to mark the different cells of the immune system with fluorescent tags of different colours. They then introduced bacteria labelled with similar coloured tags, and observed the unfolding battle live under a multiphoton microscope.

"We can use such imaging to visualise directly what happens under the skin. It allows us to see both invaders and immune cells at the same time, as well as all the structures in the skin, such as blood vessels, lymphatic vessels and hair follicles," says Professor Weninger.

The initial shock troops of the body's defence against the invading bacteria are immune cells known as neutrophils. They are stored in and launched from small blood vessels. Large immune cells called macrophages are positioned intermittently on the outside of these blood vessels.

The researchers were able to watch as clusters of neutrophils moved out from the blood vessels to fight against the bacteria. About 80 per cent emerged at points close to where macrophages were sitting. The macrophages released proteins which activate the neutrophils and guide them out of the blood vessels, the researchers say.

"But we also found that as soon as the bacteria enter the body, they release a compound called alpha-haemolysin which directly destroys the macrophages, thus disrupting the system that is marshalling the defence forces against them," says Professor Weninger.

This gives the golden staph time to breed up and overwhelm the immune system. In fact, by the time reinforcements arrive, the tissue surrounding the site of infection has begun to die, diverting the immune system into the task of cleaning up the debris.

This study and visualisation of the war against infection and the opening stages of inflammation builds upon earlier studies in which the research group was able to show how dendritic cells, the immune system's sentries, guard against invasion by the protozoan parasite, Leishmania.

Such visualisations are also being used to examine how the operation of the immune system changes over time as the body begins to wear out or age.


Story Source:

The above story is based on materials provided by Centenary Institute. Note: Materials may be edited for content and length.


Journal Reference:

  1. Arby Abtin, Rohit Jain, Andrew J Mitchell, Ben Roediger, Anthony J Brzoska, Shweta Tikoo, Qiang Cheng, Lai Guan Ng, Lois L Cavanagh, Ulrich H von Andrian, Michael J Hickey, Neville Firth, Wolfgang Weninger. Perivascular macrophages mediate neutrophil recruitment during bacterial skin infection. Nature Immunology, 2013; DOI: 10.1038/ni.2769

Cite This Page:

Centenary Institute. "Golden staph paralyzes immune defenses." ScienceDaily. ScienceDaily, 25 November 2013. <www.sciencedaily.com/releases/2013/11/131125101155.htm>.
Centenary Institute. (2013, November 25). Golden staph paralyzes immune defenses. ScienceDaily. Retrieved September 18, 2014 from www.sciencedaily.com/releases/2013/11/131125101155.htm
Centenary Institute. "Golden staph paralyzes immune defenses." ScienceDaily. www.sciencedaily.com/releases/2013/11/131125101155.htm (accessed September 18, 2014).

Share This



More Health & Medicine News

Thursday, September 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

What HealthKit Bug Means For Your iOS Fitness Apps

What HealthKit Bug Means For Your iOS Fitness Apps

Newsy (Sep. 18, 2014) Apple has delayed the launch of the HealthKit app platform, citing a bug. Video provided by Newsy
Powered by NewsLook.com
Residents Vaccinated as Haiti Fights Cholera Epidemic

Residents Vaccinated as Haiti Fights Cholera Epidemic

AFP (Sep. 18, 2014) Haitians receive the second dose of the vaccine against cholera as part of the UN's vaccination campaign. Duration: 00:34 Video provided by AFP
Powered by NewsLook.com
Artificial Sweetener Could Promote Diabetes

Artificial Sweetener Could Promote Diabetes

Newsy (Sep. 17, 2014) Doctors once thought artificial sweeteners lacked the health risks of sugar, but a new study says they can impact blood sugar levels the same way. Video provided by Newsy
Powered by NewsLook.com
Ebola Vaccine Trial Gets Underway at Oxford University

Ebola Vaccine Trial Gets Underway at Oxford University

AFP (Sep. 17, 2014) A healthy British volunteer is to become the first person to receive a new vaccine for the Ebola virus after US President Barack Obama called for action against the epidemic and warned it was "spiralling out of control." Duration: 01:02 Video provided by AFP
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:
from the past week

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