CDFD finds way to kill TB bacteria

Hyderabad: A group of researchers from the Centre for DNA Fingerprinting and Diagnostics (CDFD) here has found a potential treatment for multidrug-resistant tuberculosis (MDR-TB), which defies time-tested medicines requiring patients to undergo six to nine months of treatment.

According to research, published in ‘iScience’, Dr Sangita Mukhopadhyay and her team at the Laboratory of Molecular Cell Biology, BRIC, CDFD, targeted Mycobacterium tuberculosis (Mtb), the bacteria responsible for TB, by disrupting its ability to manipulate the host’s immune system to evade the body’s defences. This approach involves targeting specific bacterial proteins that help the bacteria survive within the host.

The research showed a ‘novel secretory effector protein’ from Mtb, called chorismate mutase (MtbCM) plays a crucial role in helping TB bacteria to survive in the body.

This protein interacts with a protein, AKAP9, in the host’s body, within the ‘Golgi network’ of immune cells, called macrophages. This interaction triggers a complex signalling cascade that ultimately leads to the production of IL-10, an anti-inflammatory cytokine. IL-10 dampens the person’s immune response, preventing the body’s defences from killing the bacteria.

According to a recent report by the World Health Organisation, India accounts for 26 per cent of the total TB cases in the world and 27 per cent of MDR TB in the world.

Dr Sangita’s team also discovered that mutating the SH3-binding domain of MtbCM reduces the bacteria's ability to produce IL-10 and thereby reduces the bacteria’s survival in the body, potentially leading to more effective treatments for drug-resistant TB.

The researchers are screening existing drugs to see if any of them can block the MtbCM-AKAP9 interaction.

Explaining the reason for the emergence of new drug-resistant TB strains, she said, “Patients need to be aware of the fact that non-adherence to the treatment course leads to new drug-resistant strains. It is important to complete their 6-9 month treatment regimen to control the disease."