Boston University study identifies molecular circuitry that helps tuberculosis survive for decades

July 03, 2013

(Boston) - In a study from Boston University's National Emerging Infectious Diseases Laboratories (NEIDL), researchers have generated a map of the cellular circuitry of Mycobacterium tuberculosis, the causative agent of human tuberculosis (TB). This information, which is being published online as an Advanced Online Publication in the journal Nature, sheds new light on the bacterium's ability to survive inactive in the human body for decades, resist treatment and cause disease.

M. tuberculosis can cause devastating infections of the lungs and other body sites. In 2011 there were 8.7 million new TB cases worldwide causing an estimated 1.4 million deaths, according to the 2012 Global Tuberculosis Report by the World Health Organization. In the United States alone, there were approximately 10,500 new cases of tuberculosis reported in 2011, according to the Centers for Disease Control, and recent TB outbreaks have been reported in Virginia, Los Angeles and South Carolina.

"We have generated the first large-scale experimental map of thousands of molecular interactions in the bacterium that enable it to cause disease," said lead author James Galagan, PhD, associate director of Systems Biology at the NEIDL and associate professor of biomedical engineering, bioinformatics and microbiology at BU. "Based on this map, we have developed the first computer models that will ultimately enable us to more easily study this challenging infectious organism and develop new drugs, therapeutics and diagnostics." Galagan and his co-investigators expanded their ongoing research of the infectious disease to the NEIDL in April 2012, after the lab had been approved for Biosafety Level 2 (BSL-2) research.

"As with any map of a previously unexplored territory, we have made a number of surprising discoveries," Galagan said. The researchers looked at the interactions of 50 transcription factors, which are proteins in cells that decide how the cell responds to its environment.

The researchers also mapped the molecular response of the bacterium to low oxygen, a condition that reflects the host environment within which the bacterium must survive. "We pinpointed many molecules, interactions and responses that appear important for the bacterium but that had been previously overlooked. These provide new avenues for combating this disease," he said.

One important process studies is the ability of the bacterium to break down cholesterol. "The bacterium is thought to eat cholesterol during infection. But it does not make its own cholesterol. It eats cholesterol derived from human cell," added Galagan. The researcher's results generate new insight into this process by uncovering the interactions that potentially link cholesterol break down to changes in the host cell environment.

The work reported utilized technologies and approached developed for the Human Genome Project. "We co-opted these approaches to study this organism that is much smaller than us, but is still quite complicated," explained Galagan, who also worked on the human genome.

In the next step, the researchers will apply these technologies to M. tuberculosis while it is residing in a macrophage, one of the body's immune cells that the bacterium tends to inhabit, in order to enhance knowledge on how it is able to survive in the body for an extended amount of time.

Boston University officials announced in April 2012 that researchers would be moving into the NEIDL and would begin TB research that had been approved for the BSL-2 laboratories.
-end-
This research was funded by the National Institute of Allergy and Infectious Diseases of the National Institute of Health, Department of Health and Human Services, the Paul G. Allen Family Foundation, the National Science Foundation Pre-doctoral Fellowship Program, and the Burroughs Wellcome Fund Award for Translational Research.

About NEIDL:

Boston University's National Emerging Infectious Diseases Laboratories is part of a national network of secure facilities studying infectious diseases that are--or have the potential to become--major public health concerns. The 192,000-square-foot, seven-story facility, located on the Boston University Medical Campus, houses BSL-2, BSL-3 and BSL-4 laboratories dedicated to the development of diagnostics, vaccines, and treatments to combat emerging and re-emerging infectious diseases. Using state-of-the-art technologies developed to conduct research in safe and secure environments, the facility was designed and constructed with the highest attention to community and laboratory safety and security.

Boston University Medical Center

Related Tuberculosis Articles from Brightsurf:

Scientists find new way to kill tuberculosis
Scientists have discovered a new way of killing the bacteria that cause tuberculosis (TB), using a toxin produced by the germ itself.

Blocking the iron transport could stop tuberculosis
The bacteria that cause tuberculosis need iron to survive. Researchers at the University of Zurich have now solved the first detailed structure of the transport protein responsible for the iron supply.

Tuberculosis: New insights into the pathogen
Researchers at the University of W├╝rzburg and the Spanish Cancer Research Centre have gained new insights into the pathogen that causes tuberculosis.

Unmasking the hidden burden of tuberculosis in Mozambique
The real burden of tuberculosis is probably higher than estimated, according to a study on samples from autopsies performed in a Mozambican hospital.

HIV/tuberculosis co-infection: Tunneling towards better diagnosis
1.2 million people in the world are co-infected by the bacteria which causes tuberculosis and AIDS.

Reducing the burden of tuberculosis treatment
A research team led by MIT has developed a device that can lodge in the stomach and deliver antibiotics to treat tuberculosis, which they hope will make it easier to cure more patients and reduce health care costs.

Tuberculosis: Commandeering a bacterial 'suicide' mechanism
The bacteria responsible for tuberculosis can be killed by a toxin they produce unless it is neutralized by an antidote protein.

A copper bullet for tuberculosis
Tuberculosis is a sneaky disease, and the number one cause of death from infectious disease worldwide.

How damaging immune cells develop during tuberculosis
Insights into how harmful white blood cells form during tuberculosis infection point to novel targets for pharmacological interventions, according to a study published in the open-access journal PLOS Pathogens by Valentina Guerrini and Maria Laura Gennaro of Rutgers New Jersey Medical School, and colleagues.

How many people die from tuberculosis every year?
The estimates for global tuberculosis deaths by the World Health Organisation (WHO) and the Institute for Health Metrics and Evaluation (IHME) differ considerably for a dozen countries, according to a study led by ISGlobal.

Read More: Tuberculosis News and Tuberculosis Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.