Study busts TB bacteria hideout

New Delhi, Jan. 30: Scientists, using bone marrow samples from members of the Idu Mishmi community in Arunachal Pradesh, have discovered a hideout in the human body where tuberculosis bacteria can lie dormant for years.

A collaborative study by Indian and US scientists has identified stem cells in the bone marrow that seem to serve as a "protective niche" for TB germs to evade the action of drugs and the human immune system.

The study, published today in the journal Science Translational Medicine, relied on samples of bone marrow cells provided by volunteers among the Idu Mishmi community living in a remote mountain range in the Lower Dibang Valley of Arunachal Pradesh. By volunteering to participate in the study, scientists say, this indigenous community has contributed to efforts to resolve a long-standing mystery of medicine.

While effective antibiotics have been available to treat and cure TB for more than 50 years, TB bacilli remain in the body despite a successful course of treatment and can cause the disease to recur after years, or even decades.

Now Bikul Das at the Stanford University Medical Centre and his collaborators have found that cells called mesenchymal stem cells (MSCs) in the bone marrow appear to provide a "long-term protective" burrow for TB bacteria.

"We think we've got their hiding place," said Das, who graduated from Gauhati Medical College and Hospital before moving abroad for study and research. "We've got evidence for the presence of TB bacteria in human bone marrow MSCs."

The researchers collected bone marrow samples from nine volunteers from the Idu Mishmi community who had successfully been treated with anti-TB medications and had been declared as cured of the disease.

They found bacterial genetic material in the MSCs from eight out of the nine bone marrow samples, and were able to isolate living TB bacteria from two clusters of the MSCs from among the nine.

"They were live, viable, but non-replicating TB bacteria," said Ista Pulu, a gynaecologist who is himself a member of the Idu Mishmi community who also collaborated in the study by motivating people to participate and helping collect samples of their bone marrow.

The scientists say the study could have used samples from other populations, as it only required patients successfully treated for TB. But Das said conducting the clinical study among the Idu Mishmis provided certain advantages.

"Firstly, the community is genetically homogeneous as they are strictly endogamous ' this homogeneous population helped us uniformly isolate enriched samples of bone marrow stem cells from each of the volunteers," Das told The Telegraph. "Secondly, I've never heard of drug resistant TB among the Idu Mishmi community. This was important as we wanted to avoid a study in a population with drug resistant TB ' our focus is persistent, dormant TB."

The Research Institute of the World's Ancient Traditions Cultures and Heritage, a non-governmental organisation in Arunachal Pradesh, and the Forsyth Institute in Cambridge, Massachusetts in the US, collaborated in the study.

"This is a fascinating result," said Gobardhan Das, an Indian scientist at the University of Kwazulu-Natal in South Africa, who was not connected with the study. Das had himself shown three years ago through a study on mice that TB bacteria draw MSCs to sites of infection in the body where they form a shield, protecting the germs from the immune system.

Scientists point out that many puzzles about the TB bacteria remain unanswered.

"We don't know how TB bacteria gets into or gets out of these cells," said Dean Felsher, professor of medicine-oncology at Stanford and a co-author of the study. "Immune cells can go throughout the body including the bone marrow, but we think they cannot as easily find TB that is in bone marrow stem cells."

The scientists said their findings will need to be confirmed through studies on bone marrow samples from other populations.

The findings imply that dormant TB may be impossible to eradicate.

While a better understanding of the mechanisms through which germs evade drugs or the human immune system should, in principle, help scientists identify new molecular targets for future drugs, the study's findings suggest that tackling dormant TB will pose a severe challenge.

"There seems to be a deep evolutionary link between stem cells and microbes," Stanford's Das said. "TB bacteria seem to have learnt to protect themselves by hiding in MSCs. It could be very difficult to develop drugs because by targeting such TB bacteria, we'd also be targeting our own stem cells."

Matches

MORE TOP STORIES TODAY

On Now: Kolkata vs Bangalore

On Now: Kolkata vs Bangalore

IPL 7, GAME 11—Bangalore bowl, Murali in, still no Gayle. KKR bring in Umesh, Lynn. More »

Kolkata bowling vs Bangalore batting might

Kolkata bowling vs Bangalore batting might

The likely return of Gayle will boost Bangalore, but the result could be determined by Kolkata's bowlers. More »

Boycotting IPL will not save cricket

Boycotting IPL will not save cricket

Boycotting the IPL as a means of protest against the grime in the game may not yield the desired results. More »

Gambhir a knock away from striking form - KKR coach

Gambhir a knock away from striking form - KKR coach

Gautam made an eight-ball duck in the opening game against Mumbai and in the second game against Delhi, he lasted only half those balls. More »

Rivals say Srini group delaying BCCI special general meeting

Rivals say Srini group delaying BCCI special general meeting

The group opposed to Srinivasan alleged that since BCCI secretary Sanjay Patel belongs to the president’s group, he was intentionally delaying the SGM… More »

April 24: A legend is born

As Sachin Tendulkar turns 41 - here's a look at some offbeat moments from the Master Blaster's innings. More »

Jadeja spins out Rajasthan in close chase

Jadeja spins out Rajasthan in close chase

IPL 7, GAME 10—Chennai beat Rajasthan by 7 runs after last-over scare. More »

Cleaning up the game starts with fans

Cleaning up the game starts with fans

... because, as recent events reveal, the BCCI has little intention of doing it. More »

SL in 'difficult place' after Farbrace exit

SL in 'difficult place' after Farbrace exit

Sri Lanka depart for assignments in Ireland and England in two weeks, and Sanath Jayasuriya suggested Marvan Atapattu would be interim head coach for those… More »

Vithanage, Priyanjan get T20 call-ups

Vithanage, Priyanjan get T20 call-ups

Herath has been rested, while the team will be without the veteran pair of Mahela Jayawardene and Kumar Sangakkara, who retired from T20 internationals… More »

Chandimal axed as T20 captain

Chandimal axed as T20 captain

Sri Lanka's cricket selectors on Wednesday sacked Dinesh Chandimal as Twenty20 captain and replaced him with Lasith Malinga, while Angelo Mathews was… More »

'BCCI should have picked panel with care'

'BCCI should have picked panel with care'

Dalmiya said that it was the first time that the BCCI had been faced with a situation where the apex court had hauled up the Board and it should have acted… More »

Farbrace is England's assistant coach

Farbrace is England's assistant coach

The ECB continued the restructuring of the England coaching set-up on Wednesday by announcing the appointment of Paul Farbrace as assistant coach. More »

SC asks Mudgal committee to continue

SC asks Mudgal committee to continue

Mukul Mudgal has communicated to the court his willingness to take up the investigation and has been asked to specify the terms and modalities on April… More »

Sri Lanka players resolve pay dispute

Sri Lanka players resolve pay dispute

The pay dispute between Sri Lanka Cricket and its 13 contracted players ended on Wednesday when the latter agreed to accept 10 percent of the participation… More »

Hope to be fit for next game - Pietersen

Hope to be fit for next game - Pietersen

With two heavy defeats at the hands of Bangalore and Chennai, Daredevils currently languish near the bottom of the table. More »

'SC decision could hurt BCCI's status'

'SC decision could hurt BCCI's status'

The Supreme Court prefers that the Justice Mudgal panel further investigate the IPL corruption scandal. More »

Mudgal panel drops bombshell in court

Mudgal panel drops bombshell in court

The Mukul Mudgal probe committee dropped a bombshell in the Supreme Court on Tuesday by making a sensational claim that it was forced to stop audio recording… More »

Perfect Punjab trounce Hyderabad

Perfect Punjab trounce Hyderabad

IPL7, GAME 9—Maxwell (95, 43b), Balaji (4-13) set up 72-run win. More »

Have the ECB played an unfair game?

Have the ECB played an unfair game?

Money talks, but it is in light of this ICC shakeup that the ECB's act of soliciting of another team's coach deteriorates from free-market aggression to… More »

Farbrace quits for England post

Farbrace quits for England post

He will assist Peter Moores who was unveiled as the new England coach on Saturday. More »

Moin appointed to manage Pakistan team

Moin appointed to manage Pakistan team

Pakistan on Monday reappointed Moin Khan as chief selector and manager of the national team, a week after fellow former captain Rashid Latif turned down… More »

Chennai smash Delhi for first win

Chennai smash Delhi for first win

IPL7, MATCH 8—Raina-led middle order, superlative catching give CSK a 93-run win. More »

'BCCI reputation lowest in 80 years'

'BCCI reputation lowest in 80 years'

The former BCCI president says he was "disillusioned" by the happenings at the emergent working committee meeting on Sunday. More »