Could our immune systems benefit from the presence of some parasites? A review article from 2008 suggests that at least in certain disease states, including Irritable Bowel Disease (IBD), the immune system may benefit from the presence of helminths or some of the molecules they secrete. A correlation has been shown between places with higher hygienic standards and those locations that see a rise in allergies, Type 1 Diabetes, and IBD. "the hygiene hypothesis" as it has come to be known, provides a promising but not completely understood link between our low parasite loads, and relatively higher levels of autoimmunity and inflammatory diseases.
An overview of gastrointestinal immune system function shows how IBD pathologies including Crohns disease and Ulcerative colitis are probably Th1 mediated. That is, T helper cells are responsible for the pattern of damage to the intestines. When mammalian immune systems respond to parasitic infections, Th2 or Tfh cells are called into duty. The different kind of T cells down regulate the activity of each other. Th1 suppresses and is suppressed by Tfh. in this way, researchers interested in helminth based therapies may be getting closer to figuring out a sound mechanism for the action of the therapies.
And the therapies are promising. Some of those studies cited showed that a treatment of
Schistosoma mansoni was sufficient to reduce induced colitis in murine model. Similar findings have been found in murine models for the tapeworm
Hymenolepis diminuta and the nematode Trichinella spiralis.
Worm based therapies already are gaining some traction in human patients, too. Pediatric Crohns disease patient was successfully treated with Trichuris suis ova. Many groups seem intent on isolating active compounds from the helminth treatments to eliminate the need to infect patients with living parasites. The culmination of these efforts may be validating to the findings that are already accruing in helminth based treatments.
Do these treatments seem plausible for future medical use? Could assumptions inherent to the culture and established medical field prove too much for their acceptance? The researchers responsible also have some of these concerns. Share your thoughts in the comments below.
1. Ruyssers NE, De Winter BY, De Man JG, et al. Worms and the treatment
of inflammatory bowel disease: are molecules the answer? Clinical &
developmental immunology. 2008;2008:567314-7.
Great post Abraham! I do believe that these treatments can be plausible for future medical use, as they're being actively tested today. My money is on the treatment you described in the last paragraph: Removing the active component of worms while still eliciting the desired Th2 and Tfh response. The removal of active worm components may make the idea of treatment more acceptable to the general population.
ReplyDeleteThis post was very insightful as to provide a model oft he exact T cells that are activated in these processes in the Helminth Model. All of this research is very intriguing and I will be interested to see further publishings on these topics as the concept is further developed. It seems that the direction the studies are heading this could be a viable treatment option before to long. I agree with John as he says that the active worm may scare the common folk away from this treatment. If a treatment could be devised that only include an inactive form the population may have less hesitations toward this treatment. I believe that with time, albeit still quite a ways away, this will could soon be something commonly found in drug stores and prescribed by doctors.
ReplyDeleteVery interesting post! The use of worm based therapies is a new and innovative approach to treating diseases like this and i am interested in seeing where this goes in the future. Switching the immune response from a Th1 to a Th2 mediated response does seem like a better alternative to some of the treatments that are currently used such as immune suppressors. I do think some people would accept this as a treatment for IBD but i would have to agree with what john said and the best chance for this would be the isolation of the active components.
ReplyDeleteI’m with everyone else here. Treating IBD with helminths is an interesting concept that I think deserves the research it’s getting. Since a strong Th2 response is ideal to counter-act IBD and the Th1 involved, perhaps it would be good to focus on what the dendritic cells will present to the lymphocytes. In immuno we learned that there is a particular protein of worms that induces a Th2 response. Maybe isolating this protein could help facilitate down regulating Th1 while also not dealing with live helminths.
ReplyDeleteI think that helminths could definitely be a plausible future treatment. Being able to switch from a Th1 response to a Th2 has been discussed in immunology and would be so much better than having the person on immune suppressants, where they could get some other array of infections.
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