Molecular Mechanism Behind Latent TB Decoded
Each year approximately 9 million new cases of Tuberculosis Infection are reported globally. Mycobacterium tuberculosis – the TB-causing bacterium can stay dormant in the body for decades till it turns infectious. In its latent form, the bacterium remains sheltered within a form of white blood cells known as macrophages.
Group of researchers from CSIR-IICB, Bose Institute & Jadavpur University have decoded the Molecular Mechanism Behind Latent TB. How the tuberculosis bacterium is released from its reservoir inside the human body.
A macrophage is an important part of the immune system. It is an amoeba-like organism and its job is to clean out the entire body of microscopic debris and germs. It’s an innate capability to track down and consume invaders like germs, viruses, fungi, viruses, and parasites. However, the scenario reverses when it comes to TB bacterium. Instead of killing it, the macrophage makes a sac-like formation known as granuloma around it. The equilibrium can last for even several decades before it gets broken resulting in the discharge of infectious germs into the human body. This can happen due to many reasons like lowered immunity due to bodily weakness or infections such as HIV.
The group has identified a protein molecule called MPT63 secreted by the bacteria – may be playing a part in the release procedure. Synthetically produced MPT63 protein molecule was subjected to various levels of acidity. The result – when the acidity value is high its structure changed dramatically. It began as what’s referred to as a beta-sheet and it turned into a helical type in the acidic condition, which prevails in the developed granuloma.
The protein, which was found to have no clear function from the folded beta-sheet, abruptly became poisonous on assuming the helical type, and got into the cell membrane, resulting in the formation of pores and consequently the death of the host cells along with the release of these germs.
“Our team would try to confirm these findings in field strains of TB bacillus and see whether they can be employed to create new therapeutic interventions,” said Dr. Krishnananda Chattopadhyay, Head of Structural Biology and Bioinformatics Division at IICB and staff leader, while talking to India Science Wire.
Besides Dr. Krishnananda, the research team comprised of Achinta Sannigrahi, Indrani Nandi, Sayantani Chall, Junaid Jibran Jawed, and Animesh. The analysis results will shortly be released in journal ACS Chemical Biology.