Researchers at Duke University Medical Center and the Durham (NC) VA hospital have gained new insight into how the body eliminates dead cells. This vital information could lead to new treatment for lupus or cancer, or for preventing infections after a trauma.The scientists found that the specialized cells (macrophages) that clear dead cells have a much more complex and important function than previously thought, according to findings published in Blood (September 15, 2003).
In 1 experiment, normal mice were injected with a large quantity of dead cells, which increased the amount of DNA in the animals? blood. In a second experiment, the researchers created mice that lacked macrophages. The mice in this group also were injected with a large quantity of dead cells. Because these genetically engineered mice lacked macrophages, the scientists expected to find all of the dead cell DNA in the mice?s bloodstream. Instead, they found no DNA from the dead cells.
The researchers theorize that, without macrophages, dead cells cannot be broken down efficiently enough for DNA to show in the bloodstream at a detectable level. Cells that are not processed by macrophages and then eliminated from the body may accumulate and cause inflammation.