By staying and multiplying within our body cells (intracellularly), various bacterial pathogens can escape our immune system. Cell breakdown, the release of microorganisms spreading, infecting the neighboring cells, causing infectious disease and tissue damage is lead by the intracellular propagation of pathogens.
To respond to this strategy, the body has a response called apoptosis or programmed cell death, which is a reaction to the cellular stress during infections and the infected cells are subjected to kill itself and by quick suicide. The immune system successfully eliminates the pathogens, as they cannot multiply because of this rapid self-destruction program of our body cells.
Researchers have already observed in the past that pathogens are capable of effectively blocking apoptosis which lets them spread and reproduce intracellularly but yet, how these bacteria outsmarted the immune system and its molecular mechanism responsible for this was largely unknown.
Now, Kashkar lab has shown that the pathogen that causes a typical cause of acute inflammatory diarrhea, shigellosis (Shigella) outsmarts programmed cell death by blocking certain enzymes effectively, so-called caspases, that act as engines that initiate apoptosis.
It was seen that the lipopolysaccharides bind and block the caspase. On the other hand, bacteria without complete LPS, spark apoptosis that blocked them from reproducing intracellularly. The immune system successfully eliminates them are infectious diseases cannot be caused any longer. Thus, an important bacterial strategy to prevent the rapid death of the host cell and establish a niche to spread has been discovered by Kashkar lab’s work.
Bacteria can outsmart apoptosis
Author: Prathibha HC