Researchers discover how tuberculosis bacterium invades cells Researchers discover how tuberculosis bacterium invades cells The bacterium that causes tuberculosis uses a surprisingly underhanded trick to invade cells, School of Medicine researchers announced recently. Understanding how the bacterium invades cells may be an important first step toward developing a vaccine to prevent tuberculosis, said Jeffrey S. Schorey, Ph.D., an instructor of medicine and lead author of a paper in the Aug. 22 issue of Science. Although such a vaccine could be developed only after many more years of study, researchers are excited about the new insight into the common and deadly microbe. Brown is a professor of medicine and of cell biology and physiology.
Tuberculosis is a growing global menace that kills more people than any other infectious disease.
Researchers have long known that M. tuberculosis makes its living by preying on macrophages, the immune system warriors that usually consume bacteria. The bacterium enters a macrophage and apparently multiplies until the cell ruptures, releasing more bacteria to attack other macrophages. Schorey, Brown and colleagues conducted test-tube studies with M. tuberculosis and a few of its close relatives including M. leprae, which causes leprosy, and M. avium, which frequently infects AIDS patients. Normally, when a bacterium enters the body, the immune system responds by tagging the bug with certain proteins that alert the macrophages. Tagging a bug requires a highly choreographed interaction of many proteins, including one called C2a.