Scientists have found the reason why the body can not protect against tuberculosis
Last reviewed: 23.04.2024
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Tuberculosis, which kills more than 2 million people every year, is caused by bacteria, known as Mycobacterium tuberculosis - or Mtb.
Target cells for mycobacteria are immunocytes. Penetrating into them, mycobacteria avoid the immune response of the body.
So far, scientists have had only a general understanding of the development of tuberculosis infection. A study of specialists from the Research Center for the Study of Infections and Immunity in Vancouver showed that mycobacteria produce a specific protein that allows them to deceive the body's safety system.
The results of the research are published in the Journal of the National Academy of Sciences.
"Mycobacteria managed to completely mislead our immune system by convincing our body that they are not there, so they are such effective killers," says Dr. Yosef Av-Gay, a research fellow at the Research Center for the Study of Infections and Immunity. "We found that cells responsible for identifying and destroying invading bacteria are exposed to deception by a particular protein that blocks the ability of immune cells to recognize and destroy mycobacteria. "
How does this happen?
Macrophages are responsible for identifying and eliminating dangerous microorganisms. Typically, macrophages, by absorbing bacteria or other infectious agents, begin to concentrate them in certain areas. Then, special cell components migrate to these controlled areas, which release acidic enzymes, dissolving the bacteria. This system works great against most infectious agents. However, in the case of tuberculosis, this immune response disconnects.
When mycobacteria begin to be absorbed by macrophages, they secrete the PtpA protein, which blocks the two separate mechanisms necessary to create an acidic environment that helps kill bacteria. As a result, mycobacteria, like the Trojan horse, continue their vital activity in the cells of the immune system, hiding from the immune system.
"We have been studying the interaction between tuberculosis bacteria and human macrophages for the past ten years," says Dr. Aw-Gay. "We are very pleased with this discovery, and by discovering the tricks that use mycobacteria, we will be able to develop more effective drugs to fight the disease."
Tuberculosis is the leading cause of death among infectious diseases in the modern world. Every 20 seconds, one person dies of tuberculosis, about 4,400 people die each day. WHO estimates that one-third of the world's population is infected with tuberculosis.
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