Navigation Links
Tuberculosis: The bacillus takes refuge in adipose cells

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.

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.

< p>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.


'"/>

Source:Public Library of Science


Related biology news :

1. NJIT Presidential Award winner takes stem cell research another step
2. Unique library of plant genes germinates, takes root at UNC
3. New influenza vaccine takes weeks to mass produce
4. Oops! Researchers publish new findings on the brains response to costly mistakes
5. Blood flow in brain takes a twist, affecting views of Alzheimers
6. HIV vaccine takes different tack to boosting immune response
7. Taking evolutions temperature: Researchers pinpoint the energy it takes to make a species
8. For Stanford scientists, RNAi gene therapy takes two steps forward, one step back
9. Pitt phage hunter takes on tuberculosis
10. The brain, traffic and nano-circuits -- e-Science takes on major challenges
11. Diabetes research takes wing thanks to long-lived fruit fly
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:6/30/2017)... June 30, 2017 Today, American Trucking ... supplier of face and eye tracking software, became ... provider program. "Artificial intelligence and ... to monitor a driver,s attentiveness levels while on ... able to detect fatigue and prevent potential accidents, ...
(Date:5/16/2017)... 2017   Bridge Patient Portal , an ... MD EMR Systems , an electronic medical record ... have established a partnership to build an interface ... GE Centricity™ products, including Centricity Practice Solution (CPS), ... These new integrations will allow healthcare delivery networks ...
(Date:4/17/2017)... 17, 2017 NXT-ID, Inc. (NASDAQ: NXTD ... filing of its 2016 Annual Report on Form 10-K on Thursday ... ... available in the Investor Relations section of the Company,s website at ... website at http://www.sec.gov . 2016 Year Highlights: ...
Breaking Biology News(10 mins):
(Date:10/9/2017)... ... 2017 , ... The award-winning American Farmer television series will feature 3 Bar ... Tuesdays at 8:30aET on RFD-TV. , With global population estimates nearing ten billion ... continue to feed a growing nation. At the same time, many of our valuable ...
(Date:10/9/2017)... ... October 09, 2017 , ... ... in the medical journal, Epilepsia, Brain Sentinel’s SPEAC® System which uses the ... in detecting generalized tonic-clonic seizures (GTCS) using surface electromyography (sEMG). The prospective ...
(Date:10/7/2017)... Mass. , Oct. 6, 2017  The ... work of three scientists, Jacques Dubochet, Joachim ... breakthrough developments in cryo-electron microscopy (cryo-EM) ... technology within the structural biology community. The winners ... Scientists can now routinely produce highly resolved, three-dimensional ...
(Date:10/5/2017)... ... October 05, 2017 , ... LabRoots , the leading ... around the world, is giving back to cancer research with a month-long promotion supporting ... Now through October 31, shoppers can use promo code PinkRibbon to get 10 percent ...
Breaking Biology Technology: