Featured Research

from universities, journals, and other organizations

Virus throws a wrench in the immune system

Date:
August 16, 2012
Source:
Helmholtz Centre for Infection Research
Summary:
The cytomegalovirus (CMV) is a member of the herpesvirus family. Although most people carry CMV for life, it hardly ever makes them sick. Researchers have now unveiled long term consequences of the ongoing presence of CMV: later in life, more and more cells of the immune system concentrate on CMV, and as a result, the response against other viruses is weakened.

T cells are immune cells important for the defence against viruses. The on-going exposure to cytomegalovirus impairs their function. In the picture: Two T cells (red) interacting with a dendritic cell, another type of immune cell.
Credit: HZI / M. Rohde

The cytomegalovirus (CMV) is a member of the herpesvirus family. Although most people carry CMV for life, it hardly ever makes them sick. Researchers from the Helmholtz Centre for Infection Research and from the USA have now unveiled long term consequences of the on-going presence of CMV: Later in life, more and more cells of the immune system concentrate on CMV, and as a result, the response against other viruses is weakened. These research results help to explain why the elderly are often more prone to infectious diseases than young people.

The viral immunologist Professor Luka Cicin-Sain, head of the junior research group "Immune Aging and Chronic Infections" at the HZI in Braunschweig, Germany, and his colleagues have now published their discovery in the open access journal PLoS Pathogens. In the article, they describe that even months after infection with CMV, mice still show weaker responses against other viruses such as the flu virus.

Most adults are infected with CMV, yet this infection goes unnoticed. Usually that is of no consequence, because in the vast majority of cases, this herpesvirus does not make them sick. Only for people with a weak immune system, like organ recipients, AIDS patients, or unborn babies infected during pregnancy, the infection is dangerous. In everyone else, the virus becomes latent and persists in the body, but is kept at bay by the immune system. "In young people this lasting activation of the immune system might even be beneficial, because an active immune system may defeat other infections rapidly. But a bright candle burns down faster," says Cicin-Sain, to clarify that the immune defence will wear out over the years. In elderly, the immune system loses function and its changes that present a clear loss of immune protection are summarily termed the "Immune risk profile," shortly IRP. A relationship between IRP and the presence of CMV has been observed in several clinical studies. However, up to now it was unclear whether IRP is a consequence of the CMV infection or, vice versa, the IRP resulted in increased susceptibility to CMV infection.

The results of Cicin-Sain's group and his American colleagues from the Oregon Health and Science University in Portland and from the College of Medicine of the University of Arizona in Tucson show that the on-going CMV presence contributes to immune ageing. "Of course the immune system ages without CMV as well," Cicin-Sain explains. On the other hand, CMV is a permanent guest that demands a growing amount of attention from the T cells, an important group of immune defence cells. The longer the mice were infected with CMV, the more of these cells were engaged with the cytomegalovirus and were missing for the fight against other pathogens. Accordingly, the immune system of CMV-infected mice could not respond well to other infections, for instance to the flu- or the West-Nile-virus. "We believe that the large number of CMV-specific T cells in the lymph nodes is likely to impair the activation of the remaining cells," the researcher concludes. What accelerated the immune defence in the young organism now becomes a burden in an old organism and takes its toll. Luka Cicin-Sain thinks a little further and summarizes: "Our results clearly show how important it would be to develop a vaccine against the cytomegalovirus, despite its low direct impact on human health."


Story Source:

The above story is based on materials provided by Helmholtz Centre for Infection Research. Note: Materials may be edited for content and length.


Journal Reference:

  1. Luka Cicin-Sain, James D. Brien, Jennifer L. Uhrlaub, Anja Drabig, Thomas F. Marandu, Janko Nikolich-Zugich. Cytomegalovirus Infection Impairs Immune Responses and Accentuates T-cell Pool Changes Observed in Mice with Aging. PLoS Pathogens, 2012; 8 (8): e1002849 DOI: 10.1371/journal.ppat.1002849

Cite This Page:

Helmholtz Centre for Infection Research. "Virus throws a wrench in the immune system." ScienceDaily. ScienceDaily, 16 August 2012. <www.sciencedaily.com/releases/2012/08/120816201618.htm>.
Helmholtz Centre for Infection Research. (2012, August 16). Virus throws a wrench in the immune system. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2012/08/120816201618.htm
Helmholtz Centre for Infection Research. "Virus throws a wrench in the immune system." ScienceDaily. www.sciencedaily.com/releases/2012/08/120816201618.htm (accessed September 2, 2014).

Share This




More Health & Medicine News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Get on Your Bike! London Cycling Popularity Soars Despite Danger

Get on Your Bike! London Cycling Popularity Soars Despite Danger

AFP (Sep. 1, 2014) Wedged between buses, lorries and cars, cycling in London isn't for the faint hearted. Nevertheless the number of people choosing to bike in the British capital has doubled over the past 15 years. Duration: 02:27 Video provided by AFP
Powered by NewsLook.com
Can You Train Your Brain To Eat Healthy?

Can You Train Your Brain To Eat Healthy?

Newsy (Sep. 1, 2014) New research says if you condition yourself to eat healthy foods, eventually you'll crave them instead of junk food. Video provided by Newsy
Powered by NewsLook.com
We've Got Mites Living In Our Faces And So Do You

We've Got Mites Living In Our Faces And So Do You

Newsy (Aug. 30, 2014) A new study suggests 100 percent of adult humans (those over 18 years of age) have Demodex mites living in their faces. Video provided by Newsy
Powered by NewsLook.com
Liberia Continues Fight Against Ebola

Liberia Continues Fight Against Ebola

AFP (Aug. 30, 2014) Authorities in Liberia try to stem the spread of the Ebola epidemic by raising awareness and setting up sanitation units for people to wash their hands. Duration: 00:41 Video provided by AFP
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