Navigation Links
Immune system protein starves 'staph' bacteria

One of the ways we defend ourselves against bacterial foes is to hide their food, particularly the metals they crave. A multi-disciplinary team led by Vanderbilt University investigators has now discovered that a protein inside certain immune system cells blocks the growth of staph bacteria by sopping up manganese and zinc.

The findings, reported Feb. 15 in Science, support the notion that binding metals to starve bacteria is a viable therapeutic option for treating localized bacterial infections. New treatment strategies are urgently needed to combat the surging number of infections and deaths caused by antibiotic-resistant forms of Staphylococcus aureus (staph), such as MRSA.

If recent estimates are accurate, the number of deaths caused by MRSA exceeds the number of deaths attributable to HIV/AIDS in the United States.

Staph is arguably the most important bacterial pathogen impacting the public health of Americans, said Eric Skaar, Ph.D., assistant professor of Microbiology and Immunology and senior author of the study.

Staph is the leading cause of pus-forming skin and soft tissue infections, the leading cause of infectious heart disease, the number one hospital-acquired infection, and one of four leading causes of food-borne illness.

And it seems as if complete and total antibiotic resistance of the organism is inevitable at this point, Skaar said.

The dire outlook motivates Skaar and his colleagues in their search for new antibiotic targets.

Skaar and Brian Corbin, Ph.D., postdoctoral fellow and lead author of the report in Science, reasoned that proteins present at the site of a staph infection might be important to the battle between the bug and the immune system, and might therefore make good targets for therapeutics. They took advantage of the fact that staph forms abscesses pimple-like infected areas in internal organs like the liver.

Because we can tell exactly where the infection is, we can look for proteins that are present only at the site of infection, Skaar said.

Using sophisticated technology called imaging mass spectrometry, the investigators identified dozens of proteins specifically expressed in staph abscesses in mice. They decided to focus on one that was particularly abundant.

The protein turned out to be calprotectin, which was discovered as a calcium-binding protein about 20 years ago and is known to inhibit bacterial and fungal growth in test tubes. But how it kills bugs was unclear.

The team demonstrated in a series of in vitro and in vivo experiments that calprotectin inhibits staph growth and that it does this by binding chelating nutrient metals, specifically manganese and zinc.

It basically starves the bacteria by stealing its food, Skaar said.

Calprotectin makes up about half of the internal content of neutrophils, the primary immune cells that respond to a staph infection. The investigators propose that calprotectin is a second weapon neutrophils employ as they wage battle in the abscess. First, neutrophils try to gobble up the bacteria. If they fail and die (staph is expert at secreting toxins that kill neutrophils), then they spill their guts, which are filled with metal-binding calprotectin sponges that soak up the metals.

The neutrophil gets the last laugh, Skaar quipped.

The work is a phenomenal merger of several cutting edge technologies, which collectively allow an unprecedented view of the host-pathogen interface, said Paul Dunman, Ph.D., assistant professor of Pathology and Microbiology at the University of Nebraska Medical Center, and a co-author of the Science paper. This discovery could lead to a new way to treat staph infections.

The findings suggest that drugs that bind metals like calprotectin does would make good antibiotics.

If we can figure out how to make a molecule that transiently binds metals, and that can be targeted to abscesses, I think that would be a great drug, Skaar said.


Contact: Craig Boerner
Vanderbilt University Medical Center

Related biology technology :

1. MedImmune Strengthens Key Leadership Functions to Further Support Recently Expanded, Rapidly Advancing Product Portfolio
2. MedImmune Submits Biologics License Application to FDA for Motavizumab
3. Peptimmune Announces First Close of Series D Private Financing
4. MedImmune Broadens Focus of Venture Capital Fund to Include New Therapeutic Areas
5. QED International Associates Announces Changes to the HealthShares(TM) Autoimmune-Inflammation and Neuroscience Indexes - Correction
6. QED International Associates Announces Changes to the HealthShares(TM) Autoimmune-Inflammation and Neuroscience Indexes
7. MedImmune Announces Seven Key Promotions and New Hires
8. AstraZeneca Bolsters Its Worldwide Biologics Division Through Integration of Cambridge Antibody Technology Into MedImmune
9. MedImmune to Present RSV Surveillance and Cost-Effectiveness Data at American Academy of Pediatrics National Conference & Exhibition
10. MedImmune Recognized by Local Volunteer Organization for Its Employees Exceptional Commitment to Community Service within Montgomery County
11. Advanced Immune Support Formula Licensed From UC Berkeley Launched
Post Your Comments:
(Date:11/26/2015)... CHESHAM , England , November 26, ... Lightpoint Medical, an innovative medical device company specializing in ... Euro grant from the European Commission as part of the ... enabling the company to carry out a large-scale clinical trial ... -->      (Logo: , ...
(Date:11/25/2015)... -- PharmAthene, Inc. (NYSE MKT: PIP) announced  today that its ... (Rights Plan) in an effort to preserve the value ... 382 of the Internal Revenue Code (Code). ... its NOLs could be substantially limited if the Company ... of the Code. In general, an ownership change occurs ...
(Date:11/25/2015)... Studies reveal the differences in species of ... way for more effective treatment for one of the most ... --> --> Gum disease is ... yet relatively little was understood about the bacteria associated with ... by researchers from the WALTHAM Centre for Pet Nutrition together ...
(Date:11/25/2015)... 2015  Neurocrine Biosciences, Inc. (Nasdaq: NBIX ) ... CEO of Neurocrine Biosciences, will be presenting at the ... New York . .   ... 5 minutes prior to the presentation to download or ... will be available on the website approximately one hour ...
Breaking Biology Technology:
(Date:11/12/2015)... 12, 2015  A golden retriever that stayed healthy ... (DMD) has provided a new lead for treating this ... Broad Institute of MIT and Harvard and the University ... Cell, pinpoints a protective gene ... disease,s effects. The Boston Children,s lab of Lou ...
(Date:11/11/2015)... MedNet Solutions , an innovative SaaS-based eClinical technology company that ... announce that it will be a Sponsor of the ... held November 17-19 in Hamburg , Germany.  ... iMedNet , MedNet,s easy-to-use, proven and affordable eClinical ... able to deliver time and cost savings of up to ...
(Date:11/9/2015)... DUBLIN , Nov. 09, 2015 /PRNewswire/ ... announced the addition of the "Global ... to their offering. --> ... "Global Law Enforcement Biometrics Market 2015-2019" ... Research and Markets ( ) ...
Breaking Biology News(10 mins):