Featured Research

from universities, journals, and other organizations

Rejuvenating the old immune system

Date:
January 27, 2010
Source:
Helmholtz Association of German Research Centres
Summary:
Thanks to the progress in health care and improved living conditions, we live longer. The price we pay: Our immune system loses functionality as we age and and the susceptibility to infections increases. Researchers in Germany are now investigating this aspect of aging using a mouse model that mimics the susceptibility to infection observed in elderly humans.

Streptococcus pyogenes
Credit: Image courtesy of Helmholtz Association of German Research Centres

Thanks to the progress in health care and improved living conditions, we live longer. The price we pay: Our immune system loses functionality as we age and the susceptibility to infections increases. Members of the infection immunology research group at the Helmholtz Center for Infection Research in Braunschweig, Germany, are investigating this aspect of aging using a mouse model that mimics the susceptibility to infection observed in elderly humans.

By comparing the immune responses of both young and old mice to bacterial infection, the researchers found that the number of macrophages -- one of the major cell populations involved in the elimination of infecting bacteria -- decreases rapidly in aged mice. This decline in the number of fighters and the associated weakness of the immune defense may be responsible for the age-associated increase in susceptibility to infections.

The HZI researchers have succeeded to enhance the resistance to an infection in aged mice by treating them with a macrophage-specific growth factor. This treatment increases the amount of macrophages in aged mice and improves their capacity to fight the infection. This study has been published in the current issue of the scientific magazine Journal of Pathology.

The main task of the immune system is to protect the body against invading pathogens. For this purpose, a variety of different cell types and molecular factors work together in a complex network. Together, they compose a highly effective defense front line. As we are getting older, our immune system changes: infections are more frequent and more severe, some immune cell types lose certain properties and their functionality declines -- in short: the immune system grows old. "Since the immune system protects our body against infections, to keep the immune system young and functional is a crucial factor for a healthy aging," says Eva Medina, head of the HZI infection immunology research group.

Much research effort is now focused on identifying age-related changes in the immune function in the hope of developing intervention strategies. "These therapies aim to strength the resistance of the elderly against infectious pathogens," says Eva Medina. The researchers from the HZI have used young mice, age two to three months, and aged animals, older than 20 months (this is the equivalent of 70 to 80 human years) to investigate specific deficiencies in the immune function that lead to the age-related increased in susceptibility to infection with the bacterium Streptococcus pyogenes. This pathogen is an important cause of severe, life-threatening infections among the elderly population. While the young animals were able to combat the infection successfully, the old mice died even if they were infected with fewer bacteria.

Afterwards, the researchers investigated the immune mechanisms involved in the control of the infection that are functional in young mice but impaired in the aged animals. They focused their studies on macrophages because these cells are the first line of defense for combating bacterial infections. The scientists found that the amount of this cell type is highly reduced in the tissue of aged mice compared to young animals. As the amount of macrophages in the organs depends on the production of a specific growth factor, the researchers evaluated if treatment with this growth factor could induce repopulation of resident tissue macrophages in aged mice and increase their resistance during infection.

"The treatment made aged mice much more resistant and they could fight much better the infection. The results of our study indicate that repeated prophylactic administration of this growth factor can help to maintain the macrophage compartment in the elderly and the fitness of the immune system," says Oliver Goldmann, scientist in the HZI research group. "Understanding the changes occurring within an ageing immunes system that increase the susceptibility to infection is essential for developing new strategies to to improve the capacity of the elderly immune system to fight and defeat pathogens."


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. Goldmann et al. Age-related susceptibility to Streptococcus pyogenes infection in mice: underlying immune dysfunction and strategy to enhance immunity. The Journal of Pathology, 2009; DOI: 10.1002/path.2664

Cite This Page:

Helmholtz Association of German Research Centres. "Rejuvenating the old immune system." ScienceDaily. ScienceDaily, 27 January 2010. <www.sciencedaily.com/releases/2010/01/100126101415.htm>.
Helmholtz Association of German Research Centres. (2010, January 27). Rejuvenating the old immune system. ScienceDaily. Retrieved September 18, 2014 from www.sciencedaily.com/releases/2010/01/100126101415.htm
Helmholtz Association of German Research Centres. "Rejuvenating the old immune system." ScienceDaily. www.sciencedaily.com/releases/2010/01/100126101415.htm (accessed September 18, 2014).

Share This



More Health & Medicine News

Thursday, September 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Artificial Sweetener Could Promote Diabetes

Artificial Sweetener Could Promote Diabetes

Newsy (Sep. 17, 2014) Doctors once thought artificial sweeteners lacked the health risks of sugar, but a new study says they can impact blood sugar levels the same way. Video provided by Newsy
Powered by NewsLook.com
Ebola Vaccine Trial Gets Underway at Oxford University

Ebola Vaccine Trial Gets Underway at Oxford University

AFP (Sep. 17, 2014) A healthy British volunteer is to become the first person to receive a new vaccine for the Ebola virus after US President Barack Obama called for action against the epidemic and warned it was "spiralling out of control." Duration: 01:02 Video provided by AFP
Powered by NewsLook.com
Obesity Rates Steady Even As Americans' Waistlines Expand

Obesity Rates Steady Even As Americans' Waistlines Expand

Newsy (Sep. 17, 2014) Researchers are puzzled as to why obesity rates remain relatively stable as average waistlines continue to expand. Video provided by Newsy
Powered by NewsLook.com
President To Send 3,000 Military Personnel To Fight Ebola

President To Send 3,000 Military Personnel To Fight Ebola

Newsy (Sep. 16, 2014) President Obama is expected to send 3,000 troops to West Africa as part of the effort to contain Ebola's spread. 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