The article, now from last week here,
focuses on discussing the role of helminths in host immunological function as a
possible treatment for IBD. The authors argue that helminths subdue their
hosts immune systems in order to colonize, and by doing so revert the over
active inflammatory response that leads to IBD.
Some of the worms looked at in this article have coevolved
with their hosts for over 100,000,000 years to live symbiotically with them. As
such, they have adopted factors and receptors nearly identical to the host,
making them adept at evading immune defenses. They can even absorb tissue and
cells from the host which help to conceal it.
An important finding in the demographics of IBD was that
less developed countries had a lower incidence rate of IBD. There are even
gradients in the US and Europe that support this evidence. For instance, early studies
into IBD found the disease more common in the northern vs southern areas of the
United States. In these areas with increased helminth infection rate, allergic
disorders are decreased, asthma is reduced, and even multiple sclerosis is less
frequent. The problem in developed countries is that the environment we grow up
in is free of such helminths giving our immune system the possibility to over
compensate.
Experiments referenced in the paper included clinical trials
in humans as well as rats and mice. In humans it is a commonly held notion that
the adaptive immune system, specifically Th1 cell activity exceeding Th2
activity, is overzealous in its production of inflammatory cytokines which in
turn leads to IBD. To enforce this, some experimental evidence was provided. In
Rats, Th1-type colitis was induced and then reverted by using the intestinal
roundworm T. Spiralis. Also, in
murine models induced with Th1-type colitis, a helminth modulating the
pro-inflammatory products INF-gamma/IL20 p40 in the colon down regulated
inflammation. Infection with a worm also showed a down regulation in the Th1
pathways of the gut by up regulating Th2 cytokines like IL4 and IL13.
Another fascinating property of these worms is the ability
to influence immune cell function by modifying cell receptors. An example of
this is H. polygyrus and mucosal T
cells. This worm induces the production of TLR4 receptors in the mucosal T cell
membrane which, upon activation, cause the cell to secrete modulating factors, TGF-B
and IL10, that help control a Th1 response instead producing pro-inflammatory
molecules.
Although this article provided great information into the
advancing field of helminth treatment, it was sorely lacking figures. Some of
the pathways and interactions explained in the article would have been much
easier to understand if a relevant figure would have been made available. The
two provided are unsatisfactory and contribute nothing to the content of the
paper.
Some of the questions I had
1) Is down regulating our immune response safe when we are constantly dealing with other types of infection? A TB study I looked at found results indicating helminth infection increased the susceptibility to TB.
2) If helminth infection decreases vaccine efficacy, wouldn’t
this be a problem in developing countries where vaccines to diseases like polio
are very important?
3) Would you rather be on immunosuppressants or helminth
therapy?
I found this article particularly interesting because it suggested ingesting worms as a method for treating IBD. This method seems gross and unconventional but for those who want a more natural treatment, this one sounds like it has potential. I, myself, am very skeptical of vaccines and treatments that are known to be made in a laboratory. It scares me to know that something synthetic and man-made is going into my body. I feel taking in something natural won’t have as many negative effects on my body. Furthermore, I know there are different cultures around the world that incorporate insects into their daily diet because they are known to have medicinal value or even as a recreational food. Ingesting worms might appear incredible odd and disgusting in our society because it is rarely done; however, in other parts of the world, it has been practiced for hundreds of years. Places such as China, Thailand, and Ghana are all familiar with entomophagy, the practice of eating insects. Thus, this idea of eating helminthes in order to treat IBD doesn’t sound that farfetched to me.
ReplyDeleteWhile I agree that the validity of the treatment seems sound, although odd, I feel ambivalent towards the natural/laboratory made comment. If it's synthetic and made in a laboratory, we know EXACTLY what's in it and how it SHOULD react. If it's a naturally occurring organic substance, like the worms, I feel like it's more variable in the reactions people will have because it isn't something we necessarily control. I guess I feel like there are more factors to take into consideration when dealing with the worms.
DeleteI agree with William. I do think it's an interesting concept, however, I personally would be very hesitant to try this treatment as it requires consumption of worms on a day to day basis. Even though, the therapy seems natural, it has the potential to harm our bodies just as equally as any chemicals. I also feel like there might be a lot of unknown factors with this treatment process and that includes how long will it be in effect and also how much of an impact would this have on an individual suffering from an active infection. I think it is also important to take into account this is an experimental therapy and can have its serious effects. I think its critical to use it with caution because it can have a huge impact in decreasing our immune responses significantly.
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