Discovering immune system invaders’ secrets
Invaders can use ways to exploit immune system cells into betraying the body. For example, tuberculosis (Mycobacterium tuberculosis) as well as its relative Mycobacterium avium use macrophages in immune cells to hide from the immune system.
The researchers have now better clarified an important part of how mycobacteria hide within the immune system. Mycobacterium avium is able to invade a macrophage and manipulate the immune cell into remaining silent rather than signaling to other cells to help.
"But once this inflammatory mechanism is turned on, it is so strong, the body reacts very promptly to turn down the reaction," Trude Helen Flo, a professor of cell biology and co-director of NTNU's Centre of Molecular Inflammation Research, said. "Otherwise, if the reaction is uncontrolled, you can have septic shock.
"Keap1 is a negative mechanism for controlling inflammation," Flo said. "But this negative reaction is also what makes us susceptible to Mycobacterium avium. The balance (in the immune system response) has to be perfect for mycobacteria to survive."
Further details are available in the Proceedings of the National Academy of Sciences.