Intestinal worm infections may not be bad

Intestinal worm infections may not be all bad, according to a new study by William C. Gause, PhD, and colleagues at UMDNJ- New Jersey Medical School. The researchers have found cytokines that help oust intestinal worm infections in mice also soothe associated lung injury and inflammation. Cytokines are proteins released by cells that in turn play a role in communications among various cells in the body. The new study has been published online in advance of print in Nature Medicine.

Many intestinal worms take a detour through the lungs en route to the gut. One such worm is Nippostrongylus brasiliensis, the equivalent in rodents to human hookworm, which currently infects over 700 million people worldwide. As this worm passes through the lungs, it induces tissue damage and inflammation.

To counter this assault, the body mobilizes a specific type of immune response called a Th2 response, which promotes expulsion of the worms. But the benefits of Th2 don't end there, according to the new research. Specific cell populations and immune proteins induced during a Th2 response to these parasites, including macrophages and interleukin (IL)-4 and -13, help to repair the worm-induced damage to the lungs. The parasite-induced Th2 response appears to activate multiple factors that are important in acute wound healing and control of inflammation, which together orchestrate an enhanced wound healing response. In mice unable to respond to these proteins, the researchers found that lung damage went unchecked.

Thus it is possible that promoting Th2 responses, triggered by parasites, may be beneficial in the treatment of wounds as well as acute lung injury caused by respiratory infections such as pneumonia.