Tuberculosis bacterium subverts basic cell functions
New findings reveal that the microbe achieves virulence by disrupting immune cells' internal processes
By Nathan Seppa
Tuberculosis microbes invading human immune cells carry a cargo that increases TB virulence by inducing the cells to act less like sentinels and more like bystanders, tests in mice show. In a report in the June 11 Nature, a team hypothesizes that this initial infection strategy lays the groundwork for TB’s uncanny ability to lie dormant in an infected person for years.
Even though TB has been studied for hundreds of years, it still guards many secrets — including precisely how it undercuts immune cells.
“Understanding the mechanisms by which the bacteria are having their way with our host cells will be very helpful in coming up with targets that we might hit,” says Kathleen McDonough, a microbiologist at the State University of New York at Albany and the Wadsworth Center of the New York State Department of Health, also in Albany.
Mycobacterium tuberculosis gets engulfed by cells called macrophages, the shock troops of the immune system. Scientists knew that the bacteria had evolved mechanisms to proliferate in these cells, but exactly how was unclear, says coauthor William Bishai, an infectious disease physician at Johns Hopkins University in Baltimore.