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 July 31, 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 July 31, 2014).

Share This




More Health & Medicine News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Health Insurers' Profits Slide

Health Insurers' Profits Slide

Reuters - Business Video Online (July 30, 2014) Obamacare-related costs were said to be behind the profit plunge at Wellpoint and Humana, but Wellpoint sees the new exchanges boosting its earnings for the full year. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Concern Grows Over Worsening Ebola Crisis

Concern Grows Over Worsening Ebola Crisis

AFP (July 30, 2014) Pan-African airline ASKY has suspended all flights to and from the capitals of Liberia and Sierra Leone amid the worsening Ebola health crisis, which has so far caused 672 deaths in Guinea, Liberia and Sierra Leone. Duration: 00:43 Video provided by AFP
Powered by NewsLook.com
At Least 20 Chikungunya Cases in New Jersey

At Least 20 Chikungunya Cases in New Jersey

AP (July 30, 2014) At least 20 New Jersey residents have tested positive for chikungunya, a mosquito-borne virus that has spread through the Caribbean. (July 30) Video provided by AP
Powered by NewsLook.com
Xtreme Eating: Your Daily Caloric Intake All On One Plate

Xtreme Eating: Your Daily Caloric Intake All On One Plate

Newsy (July 30, 2014) The Center for Science in the Public Interest released its 2014 list of single meals with whopping calorie counts. 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