"I was ecstatic," Armstrong said. "It was one of those moments that makes the rest of the slogging worthwhile."
Armstrong and colleagues Margaret Armstrong at UC Davis and Frederick Rickles at George Washington University looked at clots of blood, or its equivalent, from humans, mice, lobsters and horseshoe crabs. In all four species, they found that fluorescently tagged lipopolysaccharide was bound to the fibers of the blood clot. The toxin was too tightly attached to be readily removed by chemical treatments that remove weakly bound macromolecules from proteins.
During a sabbatical leave in the laboratory of Dr. Bruce Furie at Beth Deaconess Medical Center and Harvard University, Armstrong was also able to film clots in blood vessels of live mice and showed that these in vivo clots took up lipopolysaccharide in real time. These in vivo experiments, he said, confirm the bench-top observations and offer new insights into the pathology of sepsis.
One of the deadly consequences of septic shock is disseminated intravascular coagulation, when blood clots form rapidly throughout the body. But the new results suggest that on a small and local scale, this might be part of a protective mechanism against sepsis these intravascular clots can soak up quantities of lipopolysaccharide from the blood. They also show that rather than being a simple physical barrier, blood clots play an active and dynamic role in protecting the body from infections.
Parts of the research were carried out at the Woods Hole Marine Biological Laboratory. The work w
|Contact: Andy Fell|
University of California - Davis