Navigation Links
Researchers uncover why the body can't defend against tuberculosis
Date:11/14/2011

Tuberculosis, which kills over 2 million people each year, is caused primarily by infectious bacteria known as Mycobacterium tuberculosis or Mtb. Mtb targets human immune cells as part of its strategy to avoid detection, effectively neutralizing the body's immune response.

Up until now, scientists had a general understanding of the process, but researchers in the Immunity and Infection Research Centre at Vancouver Coastal Health Research Institute and the University of British Columbia have shown Mtb produces a specific protein that allows it to defuse and bypass the body's security system. The results are published today in The Proceedings of the National Academy of Sciences, and provide a pathway for improved treatments against this disease.

"TB has been able to completely mislead our immune systems, convincing our body it isn't there, which is why it is such an effective killer," says Dr. Yossef Av-Gay, research scientist with the Immunity and Infection Research Centre at the Vancouver Coastal Research Institute and professor in the Division of Infectious Disease at UBC Faculty of Medicine. "We discovered that the cells in charge of targeting and destroying invading bacteria are being fooled by a special protein that blocks the immune cells ability to recognize and destroy it."

Here is how it works. Macrophages are dedicated human immune cells with the role of identifying and defeating dangerous microorganisms. Normally, macrophages engulf bacteria, or other infectious agents, and contain them in an enclosed secluded environment. Then, special components of the cell (cellular organelles) move to the controlled area and release acid enzymes that dissolve the bacteria. The system works beautifully against most infectious agents. However, as Dr. Av-Gay's team found, Mtb operates in a stealth manner, turning off this immune response.

In the case of Mtb, once the bacteria become engulfed by macrophages, they secrete a protein named PtpA that disables the two separate mechanisms required for making the acidic environment that normally targets them. The end result is that Mtb lives comfortably in the immune cells, like a Trojan horse, hidden from the rest of the immune system. The bacteria then multiply inside the macrophage, and when released, they attack the body.

"We have been engaged in studying the interaction between the TB bacterium and the human macrophage over the past decade," says Dr. Av-Gay. "We are delighted with this discovery. Through learning about the tricks it uses, we now have new targets, so that we can develop better drugs against this devastating disease."

TB 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). Every 20 seconds TB kills someone, with approximately 4400 people dying every day. The WHO estimates that one-third of the world's population is infected.


'/>"/>

Contact: Lisa Carver
lisa.carver@vch.ca
604-875-4111 x61777
University of British Columbia
Source:Eurekalert

Related biology news :

1. NC State researchers get to root of parasite genome
2. Researchers find animal with ability to survive climate change
3. Researchers find an essential gene for forming ears of corn
4. Researchers note differences between people and animals on calorie restriction
5. Researchers study acoustic communication in deep-sea fish
6. Researchers discover that growing up too fast may mean dying young in honey bees
7. Researchers study how pistachios may improve heart health
8. UI researchers find potentially toxic substance present in Chicago air
9. Researchers develop new self-training gene prediction program for fungi
10. Case Western Reserve University researchers track Chernobyl fallout
11. Childrens National researchers develop novel anti-tumor vaccine
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/27/2017)... N.Y. , March 27, 2017  Catholic ... Information and Management Systems Society (HIMSS) Analytics for ... EMR Adoption Model sm . In addition, CHS ... of U.S. hospitals using an electronic medical record ... for its high level of EMR usage in ...
(Date:3/22/2017)... , March 21, 2017   Neurotechnology , ... recognition technologies, today announced the release of the ... which provides improved facial recognition using up to ... a single computer. The new version uses deep ... accuracy, and it utilizes a Graphing Processing Unit ...
(Date:3/16/2017)... , March 16, 2017 CeBIT 2017 - Against identity fraud with ... Reading ... Used combined in one project, multi-biometric solutions provide a crucial ... Used combined in ... ...
Breaking Biology News(10 mins):
(Date:5/23/2017)... ... 23, 2017 , ... Kathy Goin is joining myClin ... brings years of expertise in establishing and leading clinical operations at Sponsors including ... occupational therapist, through a variety of leadership roles in Clinical Operations, to her ...
(Date:5/22/2017)... ... May 22, 2017 , ... Stratevi, a boutique firm that ... East Coast. It has opened an office in downtown Boston at 745 Atlantic Ave. ... increasingly more important to generate evidence on the value they provide, not just to ...
(Date:5/21/2017)... ... May 20, 2017 , ... CNSDose is a genetically ... error process by finding the right antidepressant faster. CNSDose speeds recovery and ... through a personalized approach to treatment. , A peer-reviewed and published, ...
(Date:5/18/2017)... ... May 18, 2017 , ... ... The Tapas Cooking Challenge is a two-hour team-building package designed for groups of ... by Chef Jodi Abel, which include items, such as Blackened Shrimp with Edamame ...
Breaking Biology Technology: