Vancouver researchers discover missing link between TB bacteria and humans

Researchers at the University of British Columbia and Vancouver Coastal Health Research Institute have discovered how tuberculosis (TB) bacteria hide and multiply in the human body and are working toward a treatment to block this mechanism of infection.

This discovery, published today in the journal Cell Host and Microbe, describes the missing link between a TB protein and its newly discovered counterpart protein in the human body’s white blood cells (macrophages).

TB causes disease by infecting the body’s macrophages. Normally, macrophages engulf bacteria and then release powerful digestive enzymes that destroy the bacteria. The researchers found that a protein secreted by TB targets a protein in the macrophage. In doing so, TB disrupts this process, allowing it to hide and multiply within the macrophage.

The research, lead by Dr. Yossi Av-Gay, research scientist with the Immunity and Infection Research Centre at the Vancouver Coastal Research Institute and associate professor with UBC’s Faculty of Medicine, suggests that therapies that block the activity of the TB protein in macrophages would allow the body to identify TB bacteria more easily. This would prevent the establishment of active and latent tuberculosis and will lead to a new and more effective treatment for TB.

“Once inside the human macrophage, TB acts as a Trojan Horse,” says Dr. Horacio Bach, the primary author of the paper and research scientist with the Immunity and Infection Research Centre at the Vancouver Coastal Research Institute. “TB multiplies inside the macrophage and when released attack the human body. By identifying this protein we are now able to expose the hiding bacteria, which will allow the macrophages to destroy them.”

The Av-Gay lab has already taken the next step.

“Excitingly, we have also been able to engineer a specific antibody that blocks this newly discovered TB protein,” says Av-Gay. “We are now looking to collaborate with the pharmaceutical industry to come up with a therapy that can be used to block this particular mechanism, which will be an important tool in weakening TB.”

TB is called the ultimate killer. It is the leading cause of death among infectious diseases in the world today and is responsible for one in four adult preventable deaths, according to the World Health Organization (WHO). Ten million new cases of TB arise every year, killing close to two million people worldwide annually. Every 20 seconds TB kills someone and approximately 4,400 people die every day. The WHO estimates that one-third of the world’s population is infected. The current treatment regime involves taking multiple medications over an extended period of time.

Source: University of British Columbia

Related stories:

Exploding chromosomes fuel research about evolution of genetic storage
Human cells somehow squeeze two meters of double-stranded DNA into the space of a typical chromosome, a package 10,000 times smaller than the volume of genetic material it contains.
Researchers discover how rheumatoid arthritis causes bone loss
Researchers have discovered key details of how rheumatoid arthritis (RA) destroys bone, according to a study published in the Aug. 22 edition of the Journal of Biological Chemistry. The findings are already guiding attempts to design new drugs to reverse RA-related bone loss and may also address more common forms of osteoporosis with a few adjustments.
Molecular sleuths track evolution through the ribosome
A new study of the ribosome, the cell's protein-building machinery, sheds light on the oldest branches of the evolutionary tree of life and suggests that differences in ribosomal structure between the three main branches of that tree are "molecular fossils" of the early evolution of protein synthesis.
White Blood Cell Uses DNA 'Catapult' to Fight Infection
(PhysOrg.com) -- U.S. and Swiss scientists have made a breakthrough in understanding how a type of white blood cell called the eosinophil may help the body to fight bacterial infections in the digestive tract, according to research published online this week in Nature Medicine.
New evidence on benefits of breast feeding
Researchers in Switzerland and Australia are reporting identification of proteins in human breast-milk — not present in cow's milk — that may fight disease by helping remove bacteria, viruses and other dangerous pathogen's from an infant's gastrointestinal tract. Their study is scheduled for the September 5 issue of ACS' Journal of Proteome Research.
'Edible optics' could make food safer
Imagine an edible optical sensor that could be placed in produce bags to detect harmful levels of bacteria and consumed right along with the veggies. Or an implantable device that would monitor glucose in your blood for a year, then dissolve.
New step forward in search for solution to infection puzzle
Scientists at the University of York have helped to reveal more about the way bacteria can attach to human tissues. The study could help in the development of new treatments for serious heart conditions such as infective endocarditis.
Cutting the brakes on the immune system
Your immune system may have more in common with a Corvette than you thought. When a virus or bacteria enters a human body, the immune system revs up to fight and expel the invader. Once the invader is gone, the body puts on the brakes to stop the immune response.

News discussion:

General Science news