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 July 30, 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 July 30, 2014).

Share This




More Health & Medicine News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Generics Eat Into Pfizer's Sales

Generics Eat Into Pfizer's Sales

Reuters - Business Video Online (July 29, 2014) — Pfizer, the world's largest drug maker, cut full-year revenue forecasts because generics could cut into sales of its anti-arthritis drug, Celebrex. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Nigeria Ups Ebola Stakes on 1st Death

Nigeria Ups Ebola Stakes on 1st Death

Reuters - Business Video Online (July 29, 2014) — Nigerian authorities have shut and quarantined a Lagos hospital where a Liberian man died of the Ebola virus, the first recorded case of the highly-infectious disease in Africa's most populous economy. David Pollard reports Video provided by Reuters
Powered by NewsLook.com
Running 5 Minutes A Day Might Add Years To Your Life

Running 5 Minutes A Day Might Add Years To Your Life

Newsy (July 29, 2014) — According to a new study, just five minutes of running or jogging a day could add years to your life. Video provided by Newsy
Powered by NewsLook.com
Ebola Outbreak Poses Little Threat To U.S.: CDC

Ebola Outbreak Poses Little Threat To U.S.: CDC

Newsy (July 29, 2014) — The Ebola outbreak in West Africa poses little threat to Americans, according to officials with the Centers for Disease Control and Prevention. 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