Immunomodulatory activity of products from the helminth parasite Fasciola hepatica

Abstract

Helminths have evolved strategies to evade host immune responses and these have been shown to be associated with simultaneous subversion of immune responses towards bystander antigens. This phenomenon forms the basis of the hygiene hypothesis and partially explains the lower incidence of allergy and autoimmune disease observed in areas of developing countries where helminth infections are endemic. Moreover, evidence from human clinical trials has demonstrated that helminth infections can attenuate disease symptoms in patients with allergy, inflammatory bowel disease and multiple sclerosis (MS). Therefore a greater understanding of how helminth parasites modulate the immune response could give invaluable insight into the host regulatory mechanisms that control allergy and autoimmunity. Furthermore, the immunomodulatory molecules secreted by helminth parasites, or their synthetic analogues, could provide novel therapeutics against immune-mediated diseases such as MS.