Small, spiky platelets and larger red blood cells.DONALD BLISS/NATIONAL CANCER INSTITUTEPlatelets may contribute to protection against bacterial infection, according to new research published today (June 16) in Nature Immunology. Scientists found that in the livers of mice, platelets collaborated with specialized white blood cells to capture and engulf blood-borne bacteria, and this interaction helped protect the animals from bacterial infection.
“It’s an extremely exciting paper,” said Steve Watson, a platelet cell biologist at the University of Birmingham, who did not participate in the research. Though previous research had demonstrated that bacteria can activate platelets, “this work emphasizes that platelets play a day-to-day role in innate immune defense by helping remove bacteria in the liver.”
Growing evidence suggests that platelets, in addition to slowing bleeding, contribute to protection against infection. In addition to expressing many receptors important to combating pathogens, platelets have been shown to aggregate with and kill bacteria in vitro. In invertebrates, immune responses and bleeding prevention are taken care of by a single cell type, and it appears that platelets have retained both functions even as vertebrate animals evolved more specialized immune cells.
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