Navigation Links
Herpes infections: Natural killer cells activate hematopoiesis
Date:5/16/2013

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

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.


'/>"/>

Contact: Luise Dirscherl
dirscherl@lmu.de
49-892-180-2706
Ludwig-Maximilians-Universitt Mnchen
Source:Eurekalert

Related biology news :

1. How and why herpes viruses reactivate to cause disease
2. Princeton researchers identify unexpected bottleneck in the spread of herpes simplex virus
3. Novel treatment approach for bladder pain using a herpes simplex virus vector reported
4. Einstein study reveals new approach for stopping herpes infections
5. How herpesvirus invades nervous system
6. Biology professor secures grant to save West Virginias primary natural history collection
7. Validity CTO to Present Natural ID Solutions for Improving Mobile Risk Management and User Experience at NFC Solutions Summit 2012
8. Honoring the fundamental role of microbes in the natural history of our planet
9. Resveratrol may be a natural exercise performance enhancer: U of A medical research
10. Naturally adhesive
11. No matter the drilling method, natural gas is a much-needed tool to battle global warming
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/10/2016)... March 10, 2016   Unisys Corporation (NYSE: ... Protection (CBP) is testing its biometric identity solution at ... to help identify certain non-U.S. citizens leaving the ... test, designed to help determine the efficiency and accuracy of ... February and will run until May 2016. --> ...
(Date:3/9/2016)... GARDENS, Fla. , March 9, 2016 /PRNewswire/ ... management authentication and enrollment solutions, today announced the ... DigitalPersona ® Altus multi-factor authentication platform. ... and InfoSec managers to step-up security where it,s ... Washington, DC . ...
(Date:3/3/2016)... MONTEREY, Calif. , March 3, 2016 /PRNewswire/ ... Partner, launched this week highlighting advancements in flexible, ... – a record setting attendance - have gathered ... in this fast-growing field of electronics. The Flex ... a focal point for companies, R&D organizations, and ...
Breaking Biology News(10 mins):
(Date:5/4/2016)... , May 4, 2016  Bayer today announced ... compound Stivarga ® (regorafenib) tablets for the ... has met its primary endpoint of a statistically ... RESORCE, evaluated the efficacy and safety of regorafenib ... after treatment with sorafenib. The safety and tolerability ...
(Date:5/3/2016)... PUNE, India , May 3, 2016 ... Type (DNA Chip (Genomics, Drug Discovery, Gene ... Chips), End user (Academics Institutes, Diagnostics Centers), ... 2020" published by MarketsandMarkets, the market is ... 2020 from USD 7.63 Billion in 2015, ...
(Date:5/3/2016)... ... 2016 , ... Kerafast Inc., developers of an online ... globe, today announced the availability of a Zika virus antibody from Vanderbilt University. ... prevention measures for the Zika virus, the virus’s geographical distribution continues to widen ...
(Date:5/3/2016)... (PRWEB) , ... May 03, 2016 , ... ... leading fertility clinics and IVF laboratories. A contingency of reproductive endocrinologists, including ... men and women experiencing infertility and to help them build families. , Ovation ...
Breaking Biology Technology: