Episode 9 – The helminth and its host: Are parasitic worms helpful or harmful?

Dr Rowann Bowcutt – Extended Interview

In our latest podcast we wriggle into the world of the parasitic worm and discover how the immune system and parasitic worms interact with one another. We learn about the immune response required to expel parasitic worms and what goes wrong to allow the development of chronic helminth infections. We also discuss the striking relationship between parasitic worm infections and allergies and autoimmune diseases and the possibility to use helminthic therapy to treat these diseases. Our guests include Professor Andrew MacDonald, Dr Sheena Cruickshank and Dr Mark Travis from the University of Manchester. We also speak to Dr Rowann Bowcutt, a current postdoctoral researcher at NYU, who is involved in conducting clinical trials using pig whipworm eggs to treat Ulcerative Colitis.

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We begin this podcast learning about our evolutionary past and strange partnership with parasitic worms. Indeed, parasitic worm infections are extremely common in the animal kingdom and in our ancestors. Parasitic worm eggs have even been found in crusader knight graves. Over the past few hundred years, the developed world has ridden itself of these infections, however in developing countries, these helminth infections are still prevalent. In fact roughly a third of the human population has a parasitic worm infection.

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Although rarely lethal, parasitic worm infections, specifically chronic worm infections, can cause great suffering to the host.

TravisDr Mark Travis speaks to us about a novel pathway that he and his team here at the University of Manchester have uncovered that is crucial in the development of chronic helminth infections. This pathway is believed to cause the host to mount the incorrect immune response, known as a type 1 response or cell-mediated immunity, which is characterised by a pro-inflammatory response.

However, even when the immune system mounts the correct immune response that can effectively expel a parasitic worm, known as a type 2 response or a humoral immune response, this does not always prevent the host developing a chronic helminth infection. This is due to a parasitic worm’s ability to ‘dodge’ the host’s immune response. Parasitic worms can evade host immunity in a variety of different ways, which is a reflection of our evolutionary past with these organisms. Many worms have unique immunoregulatory properties allowing them to modulate our immune response, primarily by dampening and suppressing the host’s immune system.

amacdonaldIntriguingly, Professor Andrew MacDonald suggests that although parasitic worms can be dangerous for the host, by removing these parasitic worms that we have evolved with over millions of years, we may have upset the balance of our immune system. Indeed, there is a striking relationship between the incidence of parasitic worm infections and the incidence of autoimmune diseases and allergies. Where parasitic worms still thrive, autoimmune diseases and allergies are rare. In contrast, where we have eradicated our worm infestations, we see a sharp increase in the number of autoimmune diseases and allergies.

SCphotowhipwormeggsWe discuss the many hypotheses as to why this may be the case with Dr Sheena Cruickshank and how parasitic worm infections may prevent or alleviate symptoms of autoimmune diseases and allergies. Finally we discuss with Dr Rowann Bowcutt her current involvement with clinical trials using whipworm eggs from pigs to treat the autoimmune disease Ulcerative Colitis.

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Episode 2 – Interactions: Plants, soil and climate change plus scientists and the public

Hi all and welcome to the second episode of the third series! This podcast was inspired by both the current media storm surrounding the new IPCC report (although this seems to have recently subsided, being overtaken by the news of Sun journalists stealing MP’s phones and leaving climate change as ‘yesterday’s news’) and the successes of our own faculty members, be it in recent advances in their ‘field’ (this pun will be duly explained, but relates to the unique work done by Professor Richard Bardgett and other scientists here at the University of Manchester) or in their award winning abilities to communicate their research, or science in general, to a wider audience.

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