A hypothesis on the initiation of Respiratory burst/Oxidative Bursts in eukaryotic cells

Respiratory burst a.k.a Oxidative burst defines

as a rapid release of the reactive oxygen species (ROS), such as superoxide anion (O−2) and hydrogen peroxide (H2O2), by different types of cells, to play roles in defending the invasive pathogens including bacteria, as well as cell signaling etc. Furthermore, respiratory burst can also be utilized in fertilization of animals, e.g. sea urchin, which is essential for the cross-link the ovum proteins to prevent lethal polyspermy.

 In the defending invasive pathogens, NOX2 enzyme in the phagolysosome membrane is responsible for the rapid generation of ROS,e.g. superoxide via its redox centre, by transferring electrons from cytosolic NADPH to O2 in the phagosome. Once the bacterial phagocytosis is carried out, respiratory burst will be activated...

 The  fragmented DNA of any pathogens in the phagolysosome will be released into cytoplasm, which may turn out to deplete the cytoplasmic Ku70, and enhance the expression of NOX2, initiating respiratory burst.

 The so called depletion of Ku70 may happen in the way of sharing the bacteria DNA escaped from the secondary lysosome.

  In line with this postulation, any exogenous chemicals, such as proteins, once being eaten via phagocytosis by cells, may not be able to initiate the respiratory burst.