Immune modulation by helminths and the impact on the development of type 2 diabetes

The main objective of this thesis is to improve the understanding of the role of helminth infections in the development of insulin resistance, hence type 2 diabetes, and to gain insight into the immunological mechanisms underlying this possible interaction. To this end, we initiated a large scale cluster randomized controlled trial, assessing the effect of anthelmintic treatment on insulin resistance and other metabolic, as well as immunological parameters, in a rural area of Indonesia. Deworming significantly reduced the prevalence of helminths, as well as infection intensity. Although treatment did not lead to an increase of whole-body insulin resistance at the community level, a significant increase in insulin resistance was observed among helminth-infected subjects. Furthermore, by comparing immune cells of helminth-infected Indonesians before and after treatment, we gained insight into the specific cell populations that participate in the type 2 and regulatory networks, and show that treatment affects specific cell subsets in these networks. Altogether, the studies described in this thesis show that helminth infections in humans, as well as the administration of helminth molecules in obese mice, have a beneficial effect on the insulin sensitivity, and have shed light on the immunomodulatory effects of helminths.