Featured Research

from universities, journals, and other organizations

Herpes infections: Natural Killer cells activate hematopoiesis

Date:
May 16, 2013
Source:
Ludwig-Maximilians-Universitaet Muenchen (LMU)
Summary:
Infections can trigger hematopoiesis at sites outside the bone marrow – in the liver, the spleen or the skin. Researchers now show that a specific type of immune cell facilitates such “extra medullary” formation of blood cells.

Infections can trigger hematopoiesis at sites outside the bone marrow -- in the liver, the spleen or the skin. Researchers at Ludwig-Maximilians-Universitaet (LMU) in Munich now show that a specific type of immune cell facilitates such "extra medullary" formation of blood cells.

Related Articles


Balanced hematopoiesis is essential for the function of the immune system. During fetal development, hematopoiesis takes place mainly in the liver and the spleen. Later the process is delegated to the bone marrow, and this tissue normally serves as the sole source of blood cells for the rest of one's lifetime. However, certain infections can reactivate hematopoiesis at sites other than the bone marrow, a process which is referred to as "extramedullary" hematopoiesis. One of the best known inducers is the so-called cytomegalovirus (CMV), a member of the herpesvirus family, which is widespread in human populations worldwide, and can lead to serious illness in individuals with immature or otherwise compromised immune systems.

An international team led by Professor Ulrich Koszinowski at LMU's Max von Pettenkofer-Institute has now examined how this virus activates hematopoiesis in tissues other than the bone marrow. "Herpesviruses are highly species-specific," explains Dr. Stefan Jordan, the lead author on the new paper. "So, in order to study the phenomenon of extramedullary hematopoiesis in an animal model, we were forced to turn to the mouse virus." The murine CMV induces extramedullary hematopoiesis principally in the spleen.

Killing of infected cells paves the way

The new findings reveal a hitherto unsuspected link between natural killer (NK) cells and hematopoiesis. NK cells play an important role in combating CMV infections, because they are the immune system's first line of defense against the virus. In the first place, they are able to recognize and eliminate CMV-infected cells and, secondly, they synthesize and secrete signal molecules that mobilize other types of immune cells to mount a concerted attack on the pathogen.

"The decisive factor that leads to hematopoiesis at otherwise dormant sites is the ability of NK cells to find and destroy virus-infected cells," says Jordan. Extramedullary hematopoiesis is actually initiated by the inflammatory reaction that occurs as an early response to infection with CMV. But when the virus can replicate and spread to other cells, the pathogen suppresses the process. "The development of extramedullary hematopoiesis in the spleen is dependent on the capacity of NK cells to prevent virus spread by effectively eliminating infected cells," Jordan explains.

Extramedullary hematopoiesis itself thus appears to be an antiviral reaction. This in turn has obvious implications for the development of novel therapies. Thus, targeted stimulation of the mechanism that triggers the process could help to fight and resolve viral infections. Conversely, there are situations in which the immune system overshoots, and the spleen becomes so enlarged that it has to be surgically removed. "In this context, it would be particularly useful to understand how CMV suppresses extramedullary hematopoiesis -- then one might be able to exploit the mechanism to prevent rupture of the splenic capsule and life-threatening internal bleedings," Jordan concludes.


Story Source:

The above story is based on materials provided by Ludwig-Maximilians-Universitaet Muenchen (LMU). Note: Materials may be edited for content and length.


Journal Reference:

  1. Stefan Jordan, Zsolt Ruzsics, Maja Mitrović, Thomas Baranek, Jurica Arapović, Astrid Krmpotić, Eric Vivier, Marc Dalod, Stipan Jonjić, Lars Dφlken, Ulrich H. Koszinowski. Natural Killer Cells Are Required for Extramedullary Hematopoiesis following Murine Cytomegalovirus Infection. Cell Host & Microbe, 2013; 13 (5): 535 DOI: 10.1016/j.chom.2013.04.007

Cite This Page:

Ludwig-Maximilians-Universitaet Muenchen (LMU). "Herpes infections: Natural Killer cells activate hematopoiesis." ScienceDaily. ScienceDaily, 16 May 2013. <www.sciencedaily.com/releases/2013/05/130516105248.htm>.
Ludwig-Maximilians-Universitaet Muenchen (LMU). (2013, May 16). Herpes infections: Natural Killer cells activate hematopoiesis. ScienceDaily. Retrieved December 19, 2014 from www.sciencedaily.com/releases/2013/05/130516105248.htm
Ludwig-Maximilians-Universitaet Muenchen (LMU). "Herpes infections: Natural Killer cells activate hematopoiesis." ScienceDaily. www.sciencedaily.com/releases/2013/05/130516105248.htm (accessed December 19, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Friday, December 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Best Tips to Curb Holiday Carbs

The Best Tips to Curb Holiday Carbs

Buzz60 (Dec. 19, 2014) — It's hard to resist those delicious but fattening carbs we all crave during the winter months, but there are some ways to stay satisfied without consuming the extra calories. Vanessa Freeman (@VanessaFreeTV) has the details. Video provided by Buzz60
Powered by NewsLook.com
Sierra Leone Bikers Spread the Message to Fight Ebola

Sierra Leone Bikers Spread the Message to Fight Ebola

AFP (Dec. 19, 2014) — More than 100 motorcyclists hit the road to spread awareness messages about Ebola. Nearly 7,000 people have now died from the virus, almost all of them in west Africa, according to the World Health Organization. Video provided by AFP
Powered by NewsLook.com
Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) — In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Buzz60 (Dec. 19, 2014) — A double-amputee makes history by becoming the first person to wear and operate two prosthetic arms using only his mind. Jen Markham has the story. 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

 

Health & Medicine

Mind & Brain

Living & Well

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