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.
Vancouver Coastal Health Research Institute is the research body of Vancouver Coastal Health Authority, which includes BC's largest academic and teaching health sciences centres: Vancouver General Hospital, UBC Hospital, and GF Strong Rehabilitation Centre. The institute is academically affiliated with UBC Faculty of Medicine, and is one of Canada's top funded research centres, with $82.4 million in research funding for 2009/2010. www.vchri.ca.
The University of British Columbia (UBC) is one of North America's largest public research and teaching institutions, and one of only two Canadian institutions consistently ranked among the world's 40 best universities. Surrounded by the beauty of the Canadian West, it is a place that inspires bold, new ways of thinking that have helped make it a national leader in areas as diverse as community service learning, sustainability and research commercialization. UBC offers more than 55,000 students a range of innovative programs and attracts $550 million per year in research funding from government, non-profit organizations and industry through 7,000 grants.For media enquiries, please contact: Lisa Carver, Communications & Public Affairs
VCH/VCH Research Institute - 604 875-4111 x 61777 or 604 319-7533 – email@example.com
Lisa Carver | EurekAlert!
Inflammation Triggers Unsustainable Immune Response to Chronic Viral Infection
24.10.2016 | Universität Basel
Resolving the mystery of preeclampsia
21.10.2016 | Universitätsklinikum Magdeburg
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
25.10.2016 | Earth Sciences
25.10.2016 | Life Sciences
25.10.2016 | Earth Sciences