Tuberculosis bacteria have evolved to remember stressful encounters and react quickly to future stress, according to a study by computational bioengineers at Rice University and infectious disease experts at Rutgers New Jersey Medical School (NJMS).
Published online in the open-access journal mSystems, the research identifies a genetic mechanism that allows the TB-causing bacterium, Mycobacterium tuberculosis, to respond to stress rapidly and in manner that is “history-dependent,” said corresponding author Oleg Igoshin, a professor of bioengineering at Rice.
Researchers have long suspected that the ability of TB bacteria to remain dormant, sometimes for decades, stems from their ability to behave based upon past experience.
Latent TB is an enormous global problem. While TB kills about 1.5 million people each year, the World Health Organization estimates that 2-3 billion people are infected with a dormant form of the TB bacterium.
“There’s some sort of peace treaty between the immune system and bacteria,” Igoshin said. “The bacteria don’t grow, and the immune system doesn’t kill them. But if people get immunocompromised due to malnutrition or AIDS, the bacteria can be reactivated.”
One of the most likely candidates for a genetic switch that can toggle TB bacteria into a dormant state is a regulatory network that is activated by the stress caused by immune cell attacks…