Navigation Links
Pitt study: Lung lesions of TB variable, independent whether infection is active or latent
Date:12/15/2013

PITTSBURGH, Dec. 15, 2013 The lung lesions in an individual infected with tuberculosis (TB) are surprisingly variable and independent of each other, despite whether the patient has clinically active or latent disease, according to a new animal study led by researchers at the University of Pittsburgh School of Medicine. The findings, published online today in Nature Medicine, could point the way to new vaccines to prevent the hard-to-treat infection.

More than 30 percent of the world's population is infected with Mycobacterium tuberculosis, the bacterium that causes TB, yet only 5 to 10 percent of those infected develop active, contagious disease with symptoms of coughing, chest pain, night sweats and weight loss. Most have asymptomatic, or "latent," infections that are not contagious, but could become active years later.

When the lungs become infected with M. tuberculosis, the body's immune system walls off the bacteria into lesions called granulomas, explained co-senior investigator JoAnne Flynn, Ph.D., professor of microbiology and molecular genetics, Pitt School of Medicine.

"It's long been thought that the patient with a weakened immune system or some other immune vulnerability was more likely to develop active disease," Dr. Flynn said. "But to our surprise, our study showed that every infected individual has a collection of granulomas, some containing live bacteria and some that are sterile because the immune system has killed all the bacteria. So in this sense, there's no such thing as a latent or active granuloma."

For the study, the research team infected monkeys with TB and then carefully tracked the granulomas that developed in the lungs. They determined that each granuloma starts with only one bacterium, and that bacterial replication continued for about four weeks before the body counters with an adaptive immune response to kill off the invaders.

"This response was sufficient to kill all the bacteria and sterilize some granulomas, but bacteria persisted in others and spread to create new granulomas," Dr. Flynn said. "You need only one granuloma to 'go bad' in order to get active TB."

Even when an animal had a severe, active infection, some of their granulomas were sterile, indicating the immune system was capable of killing bacteria, the researchers found.

"We don't know yet why the immune response produced different results in different lesions," Dr. Flynn said. "When we develop a deeper understanding of why the immune response produced different results in different lesions, we will be closer to harnessing the right mechanisms to develop effective vaccines to prevent TB."


'/>"/>

Contact: Anita Srikameswaran
SrikamAV@upmc.edu
412-578-9193
University of Pittsburgh Schools of the Health Sciences
Source:Eurekalert

Related biology news :

1. UT Dallas study: Initial success for new tinnitus treatment
2. Drexel study: Consumers order a less unhealthy meal when the menu has nutritional labeling
3. Study: Metformin for breast cancer less effective at higher glucose concentrations
4. Study: Death by moonlight? Not always
5. Study: Acidity can change cell membrane properties
6. Penn study: Shutting off neurons helps bullied mice overcome symptoms of depression
7. Rutgers study: Worms may shed light on human ability to handle chronic stress
8. UT study: Chemical in antibacterial soaps may harm nursing babies
9. Study: Pedometer program helps motivate participants to sit less, move more
10. Study: MicroRNA cooperation mutes breast cancer oncogenes
11. Study: Environmental policies matter for growing megacities
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/2/2017)... 1, 2017  Central to its deep commitment ... worldwide, The Japan Prize Foundation today announced the ... pushed the envelope in their respective fields of ... scientists are being recognized with the 2017 Japan ... only contribute to the advancement of science and ...
(Date:1/31/2017)... 2017  Spero Therapeutics, LLC, a biopharmaceutical company ... of bacterial infections, today announced it has acquired ... Pro Bono Bio Ltd (PBB) to bolster its ... forms of Gram-negative bacteria.   The assets acquired have ... PBB group company. "The acquisition of ...
(Date:1/26/2017)...  Crossmatch, a leading provider of security and identity ... combatting fraud, waste and abuse in assistance operations around ... on Disaster Relief conference in Panama City ... and foreign assistance organizations throughout Latin America ... a largely unacknowledged problem in the foreign assistance and ...
Breaking Biology News(10 mins):
(Date:2/20/2017)... (PRWEB) , ... February 20, ... ... leading US Joint Commission Accredited venture-backed teleradiology and telemedicine company announces at ... Healthineers. USARAD services are planned to be offered via a global cloud-based ...
(Date:2/20/2017)...  Atrius Health and IBM (NYSE: IBM ... to develop a cloud based service designed to ... view of the multiple influences on an individual,s ... be designed to support shared decision making between ... nonprofit healthcare organization with 875 physicians caring for ...
(Date:2/18/2017)... Research and Markets has announced the addition ... to their offering. ... The report provides separate comprehensive analytics for the US, ... of World. Annual estimates and forecasts are provided for the period ... these markets. Market data and analytics are derived from primary and ...
(Date:2/17/2017)... , Feb. 17, 2017  Protagonist Therapeutics, Inc. ... on its oral peptide drug candidates, PTG-100 and ... the European Crohn,s and Colitis Organization (ECCO).  The ... Barcelona, Spain from February 15 – ... preclinical data on Protagonist drug candidates PTG-100 and ...
Breaking Biology Technology: