Blood Clots Prevent Deadly Bacterial Toxin from Spreading in Body
New research from the University of California, Davis suggests that blood clots may play an unexpected role in protecting the body from the effects of deadly bacteria.
Bacterial toxins, such as lipopolysaccharide (also known as endotoxin), can cause a variety of negative health effects including septic shock, which can significantly damage organs. In animals, lipopolysaccharide can cause disease and has been shown to be toxic to both horseshoe crabs and lobsters. Both of these arthropods are capable of getting blood clots in response to injury.
Senior research author Peter Armstrong, a professor of molecular and cellular biology at UC Davis, found that blood clots in horseshoe crabs and lobsters actively soak up the toxic lipopolysaccharide, reducing its release from the site of a wound into the body where it could cause disease or death.
"It's a significant addition to the short list of defenses that animals use to protect themselves against toxin-induced sepsis," Armstrong said.
Armstrong and his colleagues, including Margaret Armstrong at UC Davis and Frederick Rickles at George Washington University, tested the clotting defense in the blood of humans, mice, lobsters and horseshoe crabs. In all four species, they found lipopolysaccharide binding to the fibers of the blood clot. The bond was tight enough that it could not be readily broken by common chemical treatments that remove weakly bound macromolecules from proteins.
Ironically, one of the deadly consequences of septic shock is disseminated intravascular coagulation, which results in blood clots forming rapidly throughout the body.
Armstrong and his team's discovery suggests that on a small and local scale, blood clotting might be part of a defense mechanism against sepsis caused by lipopolysaccharide in the blood stream.
The research is published in the journal PLOS One.
The video below shows a mouse blood clot (red) capturing bacterial toxin (green). Yellow color shows toxin bound to the clot. Pieces of clot break off as blood flows past.