A team of scientists discovered that the bacteria which is responsible for Tuberculosis can be killed by a suicide toxin they produce. This study was done by the European Molecular Biology Laboratory and the Institute of Pharmacology and Structural Biology.
This study was published in the Molecular Cell on 18 February 2019.
Tuberculosis (TB) is a disease that is caused by Mycobacterium tuberculosis bacteria. This disease can spread through the air and affect all organs of the body, especially the lungs. If not treated, TB can be deadly to the human body.
The suicide toxin the bacteria produces can be neutralized with an antidote protein. The bacteria make molecules which are toxic to themselves. When these toxins are exposed to a severe environment, they slow down the growth of a bacterial population.
In some cases, the toxin can also kill the bacteria that originally produced it. The reason for this “suicide” is still unknown. There are two possibilities that can help find the answer to this.
When faced with a shortage of nutrient, the toxins sacrifice a few for the benefit of many. Or the toxins may function as an antiviral defense mechanism which kills infected bacteria.
One of the suicide toxins has been identified as MbcT. This MbcT toxin is present in the Mycobacterium tuberculosis. If an antitoxin is not used, then the MbcT toxin will kill Mycobacterium tuberculosis. This will happen by breaking down its store of NAD. NAD is a molecule which is nitpicking for sustaining life.
Olivier Neyrolles one of the lead authors of the study implied the therapeutic potential of this toxin. The researchers picked mouse and human cells and infected them with Mycobacterium tuberculosis in which there was a lack of MbcT toxin.
The researchers then artificially stimulated the making of MbcT toxin in them. Once the toxin got activated, it reduced the number of bacteria infecting cells. The mouse survival rate increased as a result.
Researchers at the European Molecular Biology Laboratory (EMBL) have determined the 3D structure of MbcT complex. The researchers are now working to find out and identify the combinations which can help free the toxin from the antidote.
The researchers say that these molecules may further help fight other infectious diseases as similar toxin and antitoxin have been identified in other harmful bacterias.