Hookworm is a gastrointestinal helminth parasite. It is a leading cause of morbidity in developing countries affecting one billion people worldwide.
Human hookworm infection is currently controlled through frequent use of antihelminthic drugs in school-age children, however, high rates of re-infection occur soon after treatment and there is evidence of emerging drug resistance. Malaghan Institute update on Hookworm Monday 27 April 2015
One interesting trend observed when communities are able to prevent helminth parasitism is that the incidence of allergies to harmless envirionmental allergens progressively begins to rise.
Parasitic worms have evolved to live for a long time in humans. In many ways, humans have also evolved to tolerate parasites, but only up to a certain point.
When it all gets too much, our immune system elicits a response called the Th2 (allergic) immune response to get rid of the parasites. Paradoxically, it is this same Th2 immune response that gives rise to the symptoms of asthma and allergy.
We do not know why the immune systems of allergic individuals respond to house dust mites, pollen or peanuts as though they were parasites. But believe it is due in part to their immune system not receiving the appropriate ‘education’ early on in life.
The parasitic worms do not want the Th2 immune response to be activated, because they do not want to be kicked out of their host, so they have ways of keeping the host immune system in check.
Professor Graham Le Gros hypothesises, that if we can learn how the worms do this, that is how they are able to suppress the allergic immune response, we could do the same to treat asthma and allergy naturally.
The role of gastrointestinal helminth parasites in regulating the immune regulatory functions mediated by the gut has become a focus of recent research attention.
Professor Graham Le Gros and colleagues seek to discover the mechanisms by which helminth parasites can suppress the sensitisation phase of the allergic immune response, with a view to guiding the design of novel therapies for treating both allergic diseases and other chronic inflammatory conditions.
In parallel to this work is a parasitology research programme dedicated to the development of a vaccine against human hookworm infection – one of the great neglected tropical diseases that keeps a billion people worldwide in a state of poor health. Parasitology has a natural link with allergic diseases because they both use the same Th2 immune response pathways.
Since vaccination is currently viewed as the only long-term solution to preventing human hookworm infection, Professor Le Gros' research team has been working hard to identify putative targets both for vaccine design and for testing the vaccine's effectiveness in the field. To do this they are studying immune responses to a harmless rodent model of human hookworm called Nippostrongylus brasiliensis and have had their findings and methodologies published in several high impact scientific journals over the past year.
This research represents a significant contribution to the global vaccine initiative against human hookworm that New Zealanders can be proud of.
Foundation for Research, Science & Technology, Health Research Council of New Zealand, Maurice Wilkins Centre, New Zealand Lottery Health Research, The Royal Society of New Zealand Marsden Fund, University of Otago, Wellington Medical Research Foundation
Click the figure below to watch the embryonic development of Nippostrongulus brasilenisis (Nb) nematode worm.