Featured Research

from universities, journals, and other organizations

Immune cells of the blood might replace dysfunctional brain cells

Date:
October 22, 2012
Source:
Helmholtz Association of German Research Centres
Summary:
Blood-circulating immune cells can take over the essential immune surveillance of the brain. A new study might indicate new ways of dealing with diseases of the nervous system.

Blood-circulating immune cells can take over the essential immune surveillance of the brain, this is shown by scientists of the German Center for Neurodegenerative Diseases (DZNE) and the Hertie Institute for Clinical Brain Research in Tübingen. Their study, now published in PNAS, might indicate new ways of dealing with diseases of the nervous system.

The immune system is composed of multiple cell types each capable of specialized functions to protect the body from invading pathogens and promote tissue repair after injury. One cell type, known as monocytes, circulates throughout the organism in the blood and enters tissues to actively phagocytose (eat) foreign cells and assist in tissue healing. While monocytes can freely enter most bodily tissues, the healthy, normal brain is different as it is sequestered from circulating blood by a tight network of cells known as the blood brain barrier. Thus, the brain must maintain a highly specialized, resident immune cell, known as microglia, to remove harmful invaders and respond to tissue damage.

In certain situations, such as during disease, monocytes can enter the brain and also contribute to tissue repair or disease progression. However, the potential for monocytes to actively replace old or injured microglia is under considerable debate. To address this, Nicholas Varvel, Stefan Grathwohl and colleagues from the German Center for Neurodegenerative Diseases (DZNE) Tübingen and the Hertie Institute for Clinical Brain Research in Tübingen used a transgenic mouse model in which almost all brain microglia cells (>95%) can be removed within two weeks. This was done by introducing a so-called suicide gene into microglia cells and administering a pharmaceutical agent that leads to acute death of the cells. Surprisingly, after the ablation of the microglia, the brain was rapidly repopulated by blood-circulating monocytes. The monocytes appeared similar, but not identical to resident microglia. The newly populated monocytes, evenly dispersed throughout the brain, responded to acute neuronal injury and other stimuli -- all activities normally assumed by microglia. Most interestingly, the monocytes were still present in the brain six months -- nearly a quarter of the life of a laboratory mouse -- after initial colonization.

These studies now published in PNAS provide evidence that blood-circulating monocytes can replace brain resident microglia and take over the essential immune surveillance of the brain. Furthermore, the findings highlight a strong homeostatic mechanism to maintain a resident immune cell within the brain. The observation that the monocytes took up long-term residence in the brain raises the possibility that these cells can be utilized to deliver therapeutic agents into the diseased brain or replace microglia when they become dysfunctional. Can monocytes be exploited to combat the consequences of Alzheimer's disease and other neurodegenerative diseases? The scientists and their colleagues in the research groups headed by Mathias Jucker are now following exactly this research avenue.


Story Source:

The above story is based on materials provided by Helmholtz Association of German Research Centres. Note: Materials may be edited for content and length.


Journal Reference:

  1. N. H. Varvel, S. A. Grathwohl, F. Baumann, C. Liebig, A. Bosch, B. Brawek, D. R. Thal, I. F. Charo, F. L. Heppner, A. Aguzzi, O. Garaschuk, R. M. Ransohoff, M. Jucker. Microglial repopulation model reveals a robust homeostatic process for replacing CNS myeloid cells. Proceedings of the National Academy of Sciences, 2012; DOI: 10.1073/pnas.1210150109

Cite This Page:

Helmholtz Association of German Research Centres. "Immune cells of the blood might replace dysfunctional brain cells." ScienceDaily. ScienceDaily, 22 October 2012. <www.sciencedaily.com/releases/2012/10/121022113428.htm>.
Helmholtz Association of German Research Centres. (2012, October 22). Immune cells of the blood might replace dysfunctional brain cells. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2012/10/121022113428.htm
Helmholtz Association of German Research Centres. "Immune cells of the blood might replace dysfunctional brain cells." ScienceDaily. www.sciencedaily.com/releases/2012/10/121022113428.htm (accessed July 28, 2014).

Share This




More Health & Medicine News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Trees Could Save More Than 850 Lives Each Year

Trees Could Save More Than 850 Lives Each Year

Newsy (July 27, 2014) — A national study conducted by the USDA Forest Service found that trees collectively save more than 850 lives on an annual basis. Video provided by Newsy
Powered by NewsLook.com
Google's Next Frontier: The Human Body

Google's Next Frontier: The Human Body

Newsy (July 27, 2014) — Google is collecting genetic and molecular information to paint a picture of the perfectly healthy human. Video provided by Newsy
Powered by NewsLook.com
What's To Blame For Worst Ebola Outbreak In History?

What's To Blame For Worst Ebola Outbreak In History?

Newsy (July 27, 2014) — A U.S. doctor has tested positive for the deadly Ebola virus, as the worst-ever outbreak continues to grow. Video provided by Newsy
Powered by NewsLook.com
Losing Sleep Leaves You Vulnerable To 'False Memories'

Losing Sleep Leaves You Vulnerable To 'False Memories'

Newsy (July 27, 2014) — A new study shows sleep deprivation can make it harder for people to remember specific details of an event. Video provided by Newsy
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