There is quiet celebration in the chemistry department at the Bose Institute here a day after news that scientists in this north Kolkata laboratory have identified a protein in the tuberculosis bacteria which weakens the body’s immune system. How this protein behaves could help researchers develop an alternate cure for TB. Tapping the protein could also control diseases caused by unwanted inflammation like rheumatoid arthritis.

The research team of Sushil Kumar Pathak and Sanchita Basu, led by senior researchers Joyoti Basu and Manikuntala Kundu, all from the Bose Institute, took two years of vigorous experimentation to isolate the protein and study its influence on receptor molecules. Their work has been published in the latest issue of the journal, Nature Immunology.

The researchers identified a protein, Early Secreted Antigen 6 (or ESAT6), that binds itself onto receptors called TLR2 on the surface of macrophages, a type of white blood cell that attacks invading viruses and bacteria.

This hinders the macrophage from producing “cytokines” — proteins released by the cells of immunity system to kill the TB bacterium.

Speaking to The Indian Express, Basu said that while it was too early to say whether this breakthrough will affect the conventional mode of TB treatment, “based on this breakthrough, researchers can now develop peptide-based therapies to control inflammatory signals like in rheumatoid arthritis.”

Moreover, while the existing conventional TB treatment like DOTS function by killing the TB bacteria with a “cocktail of drugs”, the new finding can bring out cures with a different, more targeted approach. “For instance, it gives the possibility of augmenting the host immune system unlike the existing treatments which kills TB bacteria,” said Basu.

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