Navigation Links
Gamma interferon a wake-up call for stem cell response to infection
Date:6/8/2010

HOUSTON -- (June 10, 2010) Most of the time, the body's blood-forming (hematopoietic) stem cells remain dormant, with just a few producing blood cells and maintaining a balance among the different types.

However, invading bacteria can be a call-to-arms, awaking the sleeping stem cells and prompting them to produce immune system cells that fight the foreign organisms. The "bugler" that awakes the stem cells in this battle is gamma interferon, a front-line protein defender against bacterial infection, said researchers from Baylor College of Medicine (www.bcm.edu) in a report that appears in the current issue of the journal Nature (www.nature.com).

"We are looking at the normal function of stem cells," said Dr. Margaret Goodell (www.bcm.edu/star/index.cfm?pmid=2947), professor of molecular and human genetics at BCM and director of the Stem Cells and Regenerative Medicine (STaR) (www.bcm.edu/star/index.cfm?PMID=0) Center. She is the report's senior author. "One of those is to respond to an infection."

Goodell and her colleagues knew that cells farther along in the differentiation process responded to infection, increasing the production of immune cells.

"We were sure there was a mechanism by which hematopoietic stem cells respond to infection, but it was not obvious," she said. They started their work with gamma interferon because they knew it played an important role in bacterial infection.

The collaboration and talents of two researchers in her laboratory first co-authors Drs. Megan T. Baldridge and Katherine Y. King facilitated the work with mice that led to this finding, said Goodell. Both are at BCM.

"I think our findings represent an exciting new avenue for studying hematopoiesis," said King. "By viewing the hematopoietic stem cell as the source of the immune system, we are finding fundamental ways in which the immune response affects bone marrow. This is the first time that anyone has extensively studied hematopoietic stem cells in the context of an in vivo model (a living organism) of infection."

"As a specialist in infectious diseases, I see many patients whose bone marrow no longer produces sufficient blood cells as a consequence of their infection. This is particularly relevant in chronic infections such as mycobacterial diseases (that include tuberculosis) and AIDS," said King. "Our studies lend insight into the causes of this decrease in bone marrow function during such infections, and I hope the work will someday lead to new therapies."

Studies in mice with a chronic or long-term infection called Mycobacterium avium show that a greater proportion of a particular subset of their cells called long-term hematopoietic (blood-forming) stem cells are active. Gamma interferon prompts this activity. Mice that lack gamma interferon have fewer of these stem cells active during infection.

These findings show that gamma interferon not only activates stem cells during infection, but also regulate stem cells in normal times, enabling them to maintain the types of blood cells that exist in proportion or homeostasis.

"Our model predicts that bacterial infection detected by sentinel immune cells stimulates the increased release of gamma interferon, which then travels through the blood stream to activate HSCs (hematopoietic stem cells) in the bone marrow, leading to expansion and mobilization of the immune progenitor pool (the cells that ultimately produce immune system cells)," the researchers wrote.

They found that sustained activity by the hematopoietic stem cells can lead to at least transient problems with the quality of the stem cells and their abilities to stimulate production of more immune system cells.

"One of the most important things we found is the chronic infections (such as tuberculosis or HIV/AIDS) may be lead to bone marrow exhaustion," said Baldridge. "We knew that a condition called anemia of chronic disease exists, and this could be one of the contributing factors."


'/>"/>

Contact: Glenna Picton
picton@gmail.com
713-798-4710
Baylor College of Medicine
Source:Eurekalert

Related biology news :

1. Gamma interferon could aid fight against fungal infections
2. Gamma globulin effective in treating eye infections caused by adenoviruses
3. The right response to every pathogen
4. Bacterioplankton responses to desert dust in the (sub)tropical northeast Atlantic
5. Receptor variant influences dopamine response to alcohol
6. Cheese found to improve the immune response of the elderly
7. NASA deploys planes, targets satellites to aid in oil spill response
8. Study links 1976 swine flu shot to stronger immune response to 21st century pandemic flu
9. Chronix Biomedicals serum DNA assays monitor disease activity and treatment response in MS
10. Rapid response team investigates coral disease outbreak in Kaneohe Bay, Oahu
11. Discovery that PARP protein exists in all breast tumors will help target chemo and predict response
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/19/2016)... 20, 2016 The new GEZE ... compact web-based "all-in-one" system solution for all door components. ... or the door interface with integration authorization management system, ... systems. The minimal dimensions of the access control and ... building installations offer considerable freedom of design with regard ...
(Date:4/14/2016)... April 14, 2016 BioCatch ... Detection, today announced the appointment of Eyal Goldwerger ... role. Goldwerger,s leadership appointment comes at a ... of the deployment of its platform at several of ... technology, which discerns unique cognitive and physiological factors, is ...
(Date:3/31/2016)... 2016  Genomics firm Nabsys has completed a financial ... Bready , M.D., who returned to the company in ... leadership team, including Chief Technology Officer, John Oliver ... Nurnberg and Vice President of Software and Informatics, ... Dr. Bready served as CEO of Nabsys from ...
Breaking Biology News(10 mins):
(Date:6/24/2016)...  Regular discussions on a range of subjects including policies, ... entities said Poloz. Speaking at a lecture to ... he pointed to the country,s inflation target, which is set ... "In certain areas there needs ... economic goals, why not sit down and address strategy together?" ...
(Date:6/24/2016)... (PRWEB) , ... June 24, 2016 , ... Researchers at ... most commonly-identified miRNAs in people with peritoneal or pleural mesothelioma. Their findings are the ... read it now. , Diagnostic biomarkers are signposts in the blood, lung fluid ...
(Date:6/23/2016)... , June 23, 2016   Boston ... of novel compounds designed to target cancer stemness ... has been granted Orphan Drug Designation from the ... treatment of gastric cancer, including gastroesophageal junction (GEJ) ... inhibitor designed to inhibit cancer stemness pathways by ...
(Date:6/23/2016)... June 23, 2016 Houston Methodist Willowbrook ... Cy-Fair Sports Association to serve as their official ... Houston Methodist Willowbrook will provide sponsorship support, athletic ... with association coaches, volunteers, athletes and families. ... Cy-Fair Sports Association and to bring Houston Methodist ...
Breaking Biology Technology: