TB infects nearly 2.2 billion people worldwide and causes 1.7 million annual deaths. This is largely attributed to the bacteria’s ability to stay dormant in the human body and later resurface as active disease. Dr. Das and his team have recently discovered that Mycobacterium tuberculosis(Mtb), the bacteria that causes TB, can lay dormant and thrive within bone marrow stem cells.
These new findings explain the reason why TB treated patients remain sensitive to TB tests for life and importantly, why TB treatment is so difficult and requires long periods of drug treatment. Moreover, these findings raise an alert for possible transmission of TB to patients undergoing bone marrow transplants with cells obtained from donors who may have latent TB.
This study, published in Science Translational Medicine on January 30, 2013. Another Indian,Dr. Deepjyoti Kalita from the KaviKrishna Foundation and Guwahati Medical College, was also part of the research group.
Summary of the study:
Mtb infects and persists in a dormant state for long periods of time within bone marrow (BM) stem cells. These cells constitute a unique niche or a sanctuary that provides the pathogen both immune privilege and protection from drug attack. Stem cells, like those infected by Mtb, are long living cells and possess a special machinery to exclude external molecules such as anti-TB drugs to enter their cytoplasm. Therefore, once inside these cells, Mtb benefits from this mechanism for its survival in a quiescent manner.
More about Dr. Bikul Das :
Dr. Das grew up in Assam and is a graduate of the Gauhati Medical College and Hospital .He worked in Assam and Bhutan before moving to Canada for further research. His Ph.D. work involved work on cancer at the Hospital for Sick Children, University of Toronto, Canada.
He received a prestigious grant under the Gates Foundation’s Global Health Grant in 2009 to explore the role of stem cells in the management of tubercular infection.
He moved to Stanford University Medical Center to continue with his research on stem cells, cancer and microbes.
He has won many honors and awards for his research work.