Featured Research

from universities, journals, and other organizations

New Aging Studies Improving Vaccine Efficacy For The Elderly

Date:
December 21, 2009
Source:
Trudeau Institute
Summary:
A new study demonstrates that immune system cells important for both pathogen resistance and vaccine efficacy live longer in older animals but because of this longevity acquire functional defects. The work may provide new targets for boosting immune system function in older individuals.

A new study from the Trudeau Institute in Saranac Lake, New York, demonstrates that immune system cells important for both pathogen resistance and vaccine efficacy live longer in older animals but because of this longevity acquire functional defects. The work may provide new targets for boosting immune system function in older individuals.

The well-documented decreases in immune system function that accompany aging leave elderly individuals more susceptible to numerous infectious agents than younger people. Thus many vaccines now in use are not nearly as effective in protecting older people. For example, a Journal of the American Medical Association study found that in individuals over the age of 70, influenza vaccination offered only 23 percent protection, and reduced responses have also been seen for tetanus and hepatitis vaccinations.

In previous work, Trudeau Institute Investigator Susan Swain and her colleagues demonstrated that a specific type of immune cells, called CD4 T cells, which are critical to vaccine response, become less effective with age. Robust CD4 activity is necessary for antibody production in response to infection or vaccination. (The immune system contains a number of different cell types including B cells, which manufacture antibodies, and multiple classes of T cells. CD4 T cells are a type of helper cell that stimulates B cell production and many other components of immunity.) Specifically, "naive" CD4 T cells, those that have not come into contact with or become specialized to respond to a particular pathogen, are needed to ensure protection against new pathogens as well as vigorous responses to vaccination.

In the current study, published in the October issue of the Proceedings of the National Academy of Sciences, Swain and her group showed that naοve CD4 T cells from older mice survived longer than the corresponding cells from young mice when transplanted into normal intact hosts. This finding helps to explain how older animals maintain populations of circulating CD4 T cells, even though generation of new cells in the thymus decreases dramatically with age. The Trudeau team demonstrated that the older cells were relatively resistant to cues that trigger a process known as apoptosis (from the Greek "falling leaves"), a type of orchestrated cell death, and that these cells contained lower levels of a molecule that promotes apoptosis.

But even though aged CD4 T cells enjoy longer lives, their function decays. The Swain study shows that this functional decay and longer life-span appear to be linked, with the onset of increased longevity preceding functional defects. Since age exposes cells to increasing levels of stressors such as oxidative damage (aka "free radicals") that promote changes associated with cancer, the authors speculate that the strategy of maintaining CD4 cell numbers by increasing the life spans of individual cells rather than by promoting proliferation of new cells may be a safeguard of sorts against tumor development. This hypothesis remains to be further examined, however, through future research, which will also be aimed at unraveling the connection between cellular life-span and functional decay in an effort to develop means of boosting CD4 activity, and therefore pathogen resistance and vaccine efficacy, in older individuals.

The study was funded by the National Institutes of Health and the Trudeau Institute.

 


Story Source:

The above story is based on materials provided by Trudeau Institute. Note: Materials may be edited for content and length.


Journal Reference:

  1. Age-associated increase in lifespan of naοve CD4 T cells contributes to T-cell homeostasis but facilitates development of functional defects. Proceedings of the National Academy of Sciences, October, 2009

Cite This Page:

Trudeau Institute. "New Aging Studies Improving Vaccine Efficacy For The Elderly." ScienceDaily. ScienceDaily, 21 December 2009. <www.sciencedaily.com/releases/2009/10/091005161441.htm>.
Trudeau Institute. (2009, December 21). New Aging Studies Improving Vaccine Efficacy For The Elderly. ScienceDaily. Retrieved April 18, 2014 from www.sciencedaily.com/releases/2009/10/091005161441.htm
Trudeau Institute. "New Aging Studies Improving Vaccine Efficacy For The Elderly." ScienceDaily. www.sciencedaily.com/releases/2009/10/091005161441.htm (accessed April 18, 2014).

Share This



More Health & Medicine News

Friday, April 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Scientists Create Stem Cells From Adult Skin Cells

Scientists Create Stem Cells From Adult Skin Cells

Newsy (Apr. 17, 2014) — The breakthrough could mean a cure for some serious diseases and even the possibility of human cloning, but it's all still a way off. Video provided by Newsy
Powered by NewsLook.com
Obama: 8 Million Healthcare Signups

Obama: 8 Million Healthcare Signups

AP (Apr. 17, 2014) — President Barack Obama gave a briefing Thursday announcing 8 million people have signed up under the Affordable Care Act. He blasted continued Republican efforts to repeal the law. (April 17) Video provided by AP
Powered by NewsLook.com
Is Apathy A Sign Of A Shrinking Brain?

Is Apathy A Sign Of A Shrinking Brain?

Newsy (Apr. 17, 2014) — A recent study links apathetic feelings to a smaller brain. Researchers say the results indicate a need for apathy screening for at-risk seniors. Video provided by Newsy
Powered by NewsLook.com
Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) — A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. 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