Featured Research

from universities, journals, and other organizations

Tuberculosis Bacillus Hides From Immune System In Host's Fat Cells

Date:
December 24, 2006
Source:
Public Library of Science
Summary:
A team from the Institut Pasteur has recently shown that the tuberculosis bacillus hides from the immune system in its host's fat cells. This formidable pathogen is protected against even the most powerful antibiotics in these cells, in which it may remain dormant for years. This discovery, published in PLoS ONE, sheds new light on possible strategies for fighting tuberculosis. Attempts to eradicate the bacillus entirely from infected individuals should take these newly identified reservoir cells into account.

A team from the Institut Pasteur has recently shown that the tuberculosis bacillus hides from the immune system in its host's fat cells. This formidable pathogen is protected against even the most powerful antibiotics in these cells, in which it may remain dormant for years. This discovery, published in PLoS ONE, sheds new light on possible strategies for fighting tuberculosis. Attempts to eradicate the bacillus entirely from infected individuals should take these newly identified reservoir cells into account.

Related Articles


Mycobacterium tuberculosis, the bacillus responsible for tuberculosis can hide, in a dormant state, in adipose cells throughout the body. The bacterium is protected in this cellular environment, to which the natural immune defences have little access, and is inaccessible to isoniazid, one of the main antibiotics used to treat tuberculosis worldwide. These results were obtained by Olivier Neyrolles* and his colleagues from the Mycobacterial Genetics Unit directed by Brigitte Gicquel at the Institut Pasteur, in collaboration with Paul Fornès, a pathologist from Hôpital Européen Georges Pompidou. They raise questions of considerable importance in the fight against tuberculosis.

Tuberculosis kills almost two million people worldwide every year and is considered by the World Health Organisation to represent a global health emergency. However, the bacillus is much more prevalent in the world's population than the statistics would lead us to believe, because only 5 to 10% of those infected actually develop tuberculosis. The bacillus may be present in a significant proportion of the population, remaining in a "dormant" state in the body, sometimes for years, and may be "reactivated" at any time. The risk of rea ctivation is particularly high in immunocompromised individuals, such as those infected with AIDS: the HIV virus and the tuberculosis bacillus make a formidable team, with each infectious agent facilitating the progression of the other.

Neyrolles' team first demonstrated, in cell and tissue cultures, that adipose cells served as a reservoir for Mycobacterium tuberculosis, and that this protected the bacillus against isoniazid. They then investigated whether the pathogen was present in adipose cells in humans. They did this by testing for traces of the genetic structure of the bacillus in samples from people considered not to be infected. Analyses were carried out on samples from deceased subjects from Mexico, where tuberculosis is endemic, and from Parisian districts reporting very few cases of tuberculosis.

The bacterium was detected in the adipose tissue of about a quarter of these people, all of whom were unaware they were infected, in both Mexico and France. These results suggest that the bacillus responsible for tuberculosis can remain protected in the adipose tissue of the body in the absence of any sign of disease.

This work has important implications for the prevention of this disease. It helps to explain how, many years after first testing positive for tuberculosis, people with no trace of the microbe in the lungs may develop some form of tuberculosis attacking the lungs, bones or genitals. It also suggests that isoniazid treatment, prescribed to the close friends and family of patients as a preventative measure, may in some cases not provide sufficient protection against the disease. This is particularly important for immunocompromised patients and for people with AIDS, for whom a secondary infection with tuberculosis bacillus may have very serious consequences.

This work highlights the importance of the search for new targeted therapeutic weapons, such as new antibiotics, which must be able to reach the dormant bacillus that has been hiding in adipose cells without our knowing it.

Citation: Neyrolles O, Hernández-Pando R, Pietri-Rouxel F, Fornès P, Tailleux L, et al. (2006) Is Adipose Tissue a Place for Mycobacterium tuberculosis Persistence? PLoS ONE 1(1): e43. doi:10.1371/journal.pone.0000043 (http://dx.doi.org/10.1371/journal.pone.0000043)


Story Source:

The above story is based on materials provided by Public Library of Science. Note: Materials may be edited for content and length.


Cite This Page:

Public Library of Science. "Tuberculosis Bacillus Hides From Immune System In Host's Fat Cells." ScienceDaily. ScienceDaily, 24 December 2006. <www.sciencedaily.com/releases/2006/12/061221074735.htm>.
Public Library of Science. (2006, December 24). Tuberculosis Bacillus Hides From Immune System In Host's Fat Cells. ScienceDaily. Retrieved March 29, 2015 from www.sciencedaily.com/releases/2006/12/061221074735.htm
Public Library of Science. "Tuberculosis Bacillus Hides From Immune System In Host's Fat Cells." ScienceDaily. www.sciencedaily.com/releases/2006/12/061221074735.htm (accessed March 29, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Sunday, March 29, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

S. Leone in New Anti-Ebola Lockdown

S. Leone in New Anti-Ebola Lockdown

AFP (Mar. 28, 2015) — Sierra Leone imposed a three-day nationwide lockdown Friday for the second time in six months in a bid to prevent a resurgence of the deadly Ebola virus. Duration: 01:17 Video provided by AFP
Powered by NewsLook.com
These Popular Antibiotics Can Cause Permanent Nerve Damage

These Popular Antibiotics Can Cause Permanent Nerve Damage

Newsy (Mar. 27, 2015) — A popular class of antibiotic can leave patients in severe pain and even result in permanent nerve damage. Video provided by Newsy
Powered by NewsLook.com
WH Plan to Fight Antibiotic-Resistant Germs

WH Plan to Fight Antibiotic-Resistant Germs

AP (Mar. 27, 2015) — The White House on Friday announced a five-year plan to fight the threat posed by antibiotic-resistant bacteria amid fears that once-treatable germs could become deadly. (March 27) Video provided by AP
Powered by NewsLook.com
House Ready to Pass Medicare Doc Bill

House Ready to Pass Medicare Doc Bill

AP (Mar. 26, 2015) — In rare bipartisan harmony, congressional leaders pushed a $214 billion bill permanently blocking physician Medicare cuts toward House passage Thursday, moving lawmakers closer to resolving a problem that has plagued them for years. (March 26) Video provided by AP
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:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

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