Parasitology

Review Article

Parasitic helminths: a pharmacopeia of anti-inflammatory molecules

M. J. G. JOHNSTONa1a2, J. A. MacDONALDa3a4 and D. M. McKAYa1a2 c1

a1 Gastrointestinal Research Group, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, Canada, T2N 1N4

a2 Department of Physiology and Biophysics, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, Canada, T2N 1N4

a3 Smooth Muscle Research Group, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, Canada, T2N 1N4

a4 Department of Biochemistry and Molecular Biology, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, Canada, T2N 1N4

SUMMARY

Infection with parasitic helminths takes a heavy toll on the health and well-being of humans and their domestic livestock, concomitantly resulting in major economic losses. Analyses have consistently revealed bioactive molecules in extracts of helminths or in their excretory/secretory products that modulate the immune response of the host. It is our view that parasitic helminths are an untapped source of immunomodulatory substances that, in pure form, could become new drugs (or models for drug design) to treat disease. Here, we illustrate the range of immunomodulatory molecules in selected parasitic trematodes, cestodes and nematodes, their impact on the immune cells in the host and how the host may recognize these molecules. There are many examples of the partial characterization of helminth-derived immunomodulatory molecules, but these have not yet translated into new drugs, reflecting the difficulty of isolating and fully characterizing proteins, glycoproteins and lipid-based molecules from small amounts of parasite material. However, this should not deter the investigator, since analytical techniques are now being used to accrue considerable structural information on parasite-derived molecules, even when only minute quantities of tissue are available. With the introduction of methodologies to purify and structurally-characterize molecules from small amounts of tissue and the application of high throughput immunological assays, one would predict that an assessment of parasitic helminths will yield a variety of novel drug candidates in the coming years.

(Received July 15 2008)

(Revised August 25 2008)

(Revised September 22 2008)

(Accepted October 01 2008)

(Online publication December 15 2008)

Correspondence:

c1 Corresponding author: Health Sciences Centre, HSC 1877, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, Canada T2N 1N4. Tel: +1 403 220 7362. Fax: +1 403 283 3028. E-mail: dmckay@ucalgary.ca

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