Worm holes and lung damage
New research suggests that understanding provided by parasitic worms could be used to treat serious lung injury caused by infections. The worms have been shown to trigger key elements of the immune system in mice, leading to repair of damaged tissue and reduced inflammation.
The nematode worm Nippostrongylus brasiliensis is a parasite found in the lower intestines of rodents and is similar to hookworms found in people. It often enters the body through the respiratory system where it ends up in the lungs. From there it burrows out, causing damage and inflammation on the way, and finds the oesophagus, which leads to the gut. Scientists were interested in how the body minimises the damage to the lungs as the worms burrow through the tissue.
In mice, the researchers found that the worms triggered an immune response in the lungs. So-called Type 2 helper cells of the immune system were activated by the presence of the worms and recruited to the site of damage.
These cells activated other immune cells, which cleared dead cell debris. But the researchers’ novel finding was that they also triggered signalling pathways that lead to the development of macrophage cells and the release of growth-factors. These two effects resulted in reduced inflammation and unusually rapid wound repair.
By understanding how these pathways are triggered and controlled, scientists hope that they may be able to develop therapies that induce the body to repair itself after serious respiratory infections or toxic damage.