Featured Research

from universities, journals, and other organizations

TB -- Hiding In Plain Sight

Date:
May 31, 2009
Source:
American Journal of Pathology
Summary:
Current research suggests that Mycobacterium tuberculosis can evade the immune response. The related report by Rahman et al., "Compartmentalization of immune responses in human tuberculosis: few CD8+ effector T cells but elevated levels of FoxP3+ regulatory T cells in the granulomatous lesions," appears in the June 2009 issue of the American Journal of Pathology.

Low levels of the anti-TB effector molecules perforin and granulysin in the granulomas (sold line) of a human TB-infected lymph node. Note the granular and polarized expression of the cytolytic effector molecules in cells located outside the lesions.
Credit: Rahman et al, 2009

Current research suggests that Mycobacterium tuberculosis can evade the immune response.

More than two million people worldwide die from tuberculosis infection every year. Due in part to inappropriate antibiotic usage, there are a rising number (0.5 million in 2007) of cases of multidrug-resistant (MDR-TB) and extensively drug-resistant (XDR-TB) tuberculosis. New therapies are needed to treat these dangerous infections.

Immune responses to tuberculosis rarely result in complete eradication of the infection. Instead, TB-infected immune cells promote the generation of chronic inflammation and the formation of granulomas, which are areas where the bacteria are contained but not destroyed. A group led by Dr. Susanna Grundstrom Brighenti at the Karolinska Institutet in Stockholm, Sweden therefore examined the immune response in patients infected with tuberculosis.

This is the first study describing the immunoregulatory mechanism associated with the development of clinical disease at the site of infection in human TB. They found that while the immune cells responsible for killing the tuberculosis bacteria surrounded the granuloma, these cells had low levels of the molecules necessary to kill the TB. Instead, granulomas had high numbers of regulatory immune cells. These regulatory cells suppress the immune response, resulting in the survival of the tuberculosis bacteria and perhaps contributing to persistent long-term infection.

This study by Rahman et al "provide[s] evidence that the adaptive immune response in establishment of clinical TB [is] skewed towards a suppressive or regulatory phenotype that may inhibit proper immune activation and down-regulate the host response at the local site of infection. Compartmentalization of the immune response in human TB could be part of the reason why infection is never completely eradicated but instead develops into a chronic disease." In future studies, Dr. Grundstrom Brighenti and colleagues plan to "pursue new strategies developed to enhance cell-mediated immune responses that are known to provide protective immunity in patients with TB. Such an approach may involve targeting of certain subpopulations of immune cells with anti-inflammatory or immunoregulatory properties."

This work was supported by grants from the Swedish Society for Medical Research (SSMF), the Swedish Foundation for Strategic Research (SSF), Sida/SAREC, the Swedish Research Council (VR), the Swedish Heart and Lung Foundation (HLF) and the National Board of Health and Wealth fare.


Story Source:

The above story is based on materials provided by American Journal of Pathology. Note: Materials may be edited for content and length.


Journal Reference:

  1. Rahman et al. Compartmentalization of Immune Responses in Human Tuberculosis. Few CD8 Effector T Cells but Elevated Levels of FoxP3 Regulatory T Cells in the Granulomatous Lesions. American Journal Of Pathology, 2009; DOI: 10.2353/ajpath.2009.080941

Cite This Page:

American Journal of Pathology. "TB -- Hiding In Plain Sight." ScienceDaily. ScienceDaily, 31 May 2009. <www.sciencedaily.com/releases/2009/05/090522081205.htm>.
American Journal of Pathology. (2009, May 31). TB -- Hiding In Plain Sight. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2009/05/090522081205.htm
American Journal of Pathology. "TB -- Hiding In Plain Sight." ScienceDaily. www.sciencedaily.com/releases/2009/05/090522081205.htm (accessed April 23, 2014).

Share This



More Health & Medicine News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Big Pharma Braces for M&A Wave

Big Pharma Braces for M&A Wave

Reuters - Business Video Online (Apr. 22, 2014) Big pharma on the move as Novartis boss, Joe Jimenez, tells Reuters about plans to transform his company via an asset exchange with GSK, and Astra Zeneca shares surge on speculation that Pfizer is looking for a takeover. Joanna Partridge reports. Video provided by Reuters
Powered by NewsLook.com
Study Says Most Crime Not Linked To Mental Illness

Study Says Most Crime Not Linked To Mental Illness

Newsy (Apr. 22, 2014) A new study finds most crimes committed by people with mental illness are not caused by symptoms of their illness or disorder. Video provided by Newsy
Powered by NewsLook.com
Hagel Gets Preview of New High-Tech Projects

Hagel Gets Preview of New High-Tech Projects

AP (Apr. 22, 2014) Defense Secretary Chuck Hagel is given hands-on demonstrations Tuesday of some of the newest research from DARPA _ the military's Defense Advanced Research Projects Agency program. (April 22) Video provided by AP
Powered by NewsLook.com
How Smaller Plates And Cutlery Could Make You Feel Fuller

How Smaller Plates And Cutlery Could Make You Feel Fuller

Newsy (Apr. 22, 2014) NBC's "Today" conducted an experiment to see if changing the size of plates and utensils affects the amount individuals eat. 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