Infecting about nine million people worldwide every year, Tuberculosis is a deadly disease. Out of the nine million people infected from the disease, 32 per cent are from India. Many people don’t even realise that they have the infection as it remains dormant for years before becoming infectious.The tuberculosis bacterium is hunted by the white blood cells called macrophages. A macrophage is an important part of our immune system. The term literally means big eaters. A macrophage is an amoeba-like organism and it’s work to clean the body of microscopic invaders and debris. The macrophage has the innate ability to consume all the invaders including fungi, viruses, bacteria and parasites. But instead of killing the bacteria, it forms a sac-like body called granuloma around it, which keeps the bacteria dormant for as long as it’s present.But this sac can get ruptured when your immunity is lowered due to weakness or any other illness like HIV. TB is a leading killer amongst people who are infected with HIV.A team of scientists from the Kolkata-based Council of Scientific and Industrial Research (CSIR) - Indian Institute of Chemical Biology, Bose Institute in Kolkata and Jadavpur University found how tuberculosis is released from the sacs granuloma formed by the macrophages around them. The granuloma keeps the TB bacteria under control. The topic has been researched and studied for years with no positive result.Scientists found that these TB bacteria secrete a protein called MPT63, which might be the reason behind the sac break. When there is acidity, these protein structures change their formation and suddenly become toxic to the host cells (macrophages). This ends up killing the cell and releasing the bacteria.Dr Krishnananda Chattopadhyay, the Head of Structural Biology and Bioinformatics Division said, “Our team would now try to validate these findings in field strains of TB bacillus and see whether they can be used to develop new therapeutic interventions”.Now with this discovery, scientists will begin looking for methods to negate the effect of the MPT63 protein. Keeping the TB locked-in permanently and saving millions of patients every year.The results of the study will be published in the Journal of ACS Chemical Biology.