Tuberculosis kills about 1.5 million people worldwide each year. Among infectious diseases, it’s currently second only to COVID-19 as a cause of death. The interaction of the disease’s causative agent, Mycobacterium tuberculosis (Mtb), with its hosts is complex, and there are many unanswered questions about the infection, including why it can linger in the body for months or years. Now, in a study conducted on monkeys and published in Cell Reports on May 17, University of Pittsburgh researchers find that a key subset of infection-fighting immune cells only become fully active three months after the body first encounters Mtb, with a second subset of these cells emerging five months postinfection. The results suggest that a delayed adaptive immune response might be crucial to Mtb’s ability to establish a foothold in a host.
“That [the] TB immune response is unusual compared to other pathogens had been known for years, but people ...
