Lung cells new target in TB treating method

13Jan 2020
The Guardian
Lung cells new target in TB treating method

IRISH scientists have discovered a way to improve treatment for tuberculosis.

The disease is an infection caused by a bacterium called Mycobacterium tuberculosis. Although it is one of the oldest known diseases, it remains the world's deadliest infectious disease.

While it is rampant in Africa, the growing problem of antibiotic resistance is posing a significant threat worldwide.

It infects our lung macrophage cells and then manipulates them to its benefit, creating a safe home for it to hide out unperturbed, sometimes for years.

Scientists from Trinity University in the Irish Republic have discovered both how TB puts the brakes on our immune systems and how we can kick-start them back into gear – providing hope that improved treatment options could soon be on the horizon.

They had been examining how lung immune cells fuel aid the fight against infection. This work has been at the forefront of showing how the simple sugar, glucose, is used to promote macrophages anti-bacterial activities.

Trinity scientists found that persistent infection of these macrophages with TB hampers our glucose-filled engines.

This in effect shuts down the body's natural response to infection, allowing the bacteria to hide undisturbed.

Dr Frederick Sheedy of Trinity Chemistry Department explained the study also offers some hope for the future.

 "We found that when TB-infected cells are treated with a key ‘interferon gamma protein signal,' which is normally produced following vaccination, they will remove this microRNA to effectively relieve the brake and restore our normal immune response."

Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and DNA are nucleic acids, and along with lipids, proteins and carbohydrates, constitute the four major macromolecules essential for all known forms of life.

Dr Sheedy believes the research could have major implications for the future treatment of TB.

"What is particularly promising from a societal impact perspective is that as well as increasing our knowledge of how TB corrupts our normal immune response to infection, our identification of the microRNA-21 means that scientists should be able to develop improved immunotherapies or vaccine strategies to help in the fight against TB infection,” he said.

The research was funded by grants from Science Foundation Ireland, the Health Research Board, the Royal City of Dublin Hospital Trust, the Irish Research Council and the National Institutes of Health.