Scientific Abstract
Proposal No. IBD-0234R
Principal Investigator: Irma van Die, Ph.D.
Applicant Organization: VU University Medical Center (Amsterdam, The Netherlands)
Project Title: Protection against inflammatory bowel disease by glycan antigens
Period of Award: November 1, 2008 - July 31, 2011
Recent clinical trials have shown that IBD can be treated effectively by administration of eggs from the helminth Trichuris suis, which develop into adult worms in the intestines and strongly diminish the inflammation associated with IBD. Treatment with live worms has little or no side effects and thus provides a very attractive alternative to current treatments based on suppressing the inflammatory response. The major aim of this proposal is to identify the anti-inflammatory helminth components, to enable the future development of a safe and effective therapy against IBD based on defined components. Our hypothesis is that specific carbohydrate (glycan) antigens expressed on the worms are responsible for suppression of T-cell mediated inflammatory responses, and thus may be the components that have therapeutic potential. Thus, the rationale of this project is that identification of the glycans that define the immunosuppressive properties of helminths will combine the advantage of the established anti-inflammatory effects of a natural agent, with the lack of potential invasive properties of a living parasite. We believe that this approach may lead to a novel therapeutic approach for IBD that is both safe and effective.
We will enrich anti-inflammatory glycan components from total helminth extracts using several biochemical fractionation methods. The obtained fractions will be tested for their anti-inflammatory potential using highly sensitive, functional assays with human dendritic cells (DCs). DCs regulate the onset and type of T-cell mediated inflammation, and thus are a very attractive cell population to target in a therapeutic approach for IBD.
DCs will be activated in vitro using defined microbial components (such as LPS) and their activation status will be determined by measuring the expression of DC surface markers (CD80, CD86) and secretion of inflammatory cytokines, such as IL-12 that plays a key role in the onset of intestinal inflammation in IBD. Our preliminary data show that total extracts from the helminth Schistosoma mansoni completely suppress the maturation and IL-12 production of LPS-stimulated DCs, and that this effect is glycan-dependent. The structures of the glycans, and the mechanism by which the glycans exert their anti-inflammatory properties, are not known. We will dissect the helminth extracts that suppress maturation and IL-12 production from DCs until pure fractions are obtained. The glycan moieties will be analyzed by a combination of mass-spectrometry, glycosidase treatments and linkage analysis to structurally characterize the anti-inflammatory components. The purified glycan-moieties will be coupled to a protein or lipid carrier and their anti-inflammatory properties further evaluated in functional assays using isolated lamina propria and peripheral blood mononuclear cells from patients with IBD, and in vivo in a murine model of experimental colitis.
While it is clear that glycan structures can interact with immune cells and modulate their function, the structural requirements of glycans to modulate inflammatory responses, and the molecular mechanisms involved, are largely unknown. Our proposal is interdisciplinary and highly innovative because we use unique glycochemical approaches to investigate functional pathways within DCs at a molecular level, and translate the obtained knowledge to develop an improved and safe therapy for IBD.
The results of these studies will have a great impact on our general understanding of the immune mechanisms that modulate inflammatory responses. Most importantly, these studies may lead to the development of a safe and effective therapy for the treatment of IBD, and possibly other Th1-based inflammatory diseases.
Principal Investigator: Irma van Die, Ph.D.
Applicant Organization: VU University Medical Center (Amsterdam, The Netherlands)
Project Title: Protection against inflammatory bowel disease by glycan antigens
Period of Award: November 1, 2008 - July 31, 2011
Recent clinical trials have shown that IBD can be treated effectively by administration of eggs from the helminth Trichuris suis, which develop into adult worms in the intestines and strongly diminish the inflammation associated with IBD. Treatment with live worms has little or no side effects and thus provides a very attractive alternative to current treatments based on suppressing the inflammatory response. The major aim of this proposal is to identify the anti-inflammatory helminth components, to enable the future development of a safe and effective therapy against IBD based on defined components. Our hypothesis is that specific carbohydrate (glycan) antigens expressed on the worms are responsible for suppression of T-cell mediated inflammatory responses, and thus may be the components that have therapeutic potential. Thus, the rationale of this project is that identification of the glycans that define the immunosuppressive properties of helminths will combine the advantage of the established anti-inflammatory effects of a natural agent, with the lack of potential invasive properties of a living parasite. We believe that this approach may lead to a novel therapeutic approach for IBD that is both safe and effective.
We will enrich anti-inflammatory glycan components from total helminth extracts using several biochemical fractionation methods. The obtained fractions will be tested for their anti-inflammatory potential using highly sensitive, functional assays with human dendritic cells (DCs). DCs regulate the onset and type of T-cell mediated inflammation, and thus are a very attractive cell population to target in a therapeutic approach for IBD.
DCs will be activated in vitro using defined microbial components (such as LPS) and their activation status will be determined by measuring the expression of DC surface markers (CD80, CD86) and secretion of inflammatory cytokines, such as IL-12 that plays a key role in the onset of intestinal inflammation in IBD. Our preliminary data show that total extracts from the helminth Schistosoma mansoni completely suppress the maturation and IL-12 production of LPS-stimulated DCs, and that this effect is glycan-dependent. The structures of the glycans, and the mechanism by which the glycans exert their anti-inflammatory properties, are not known. We will dissect the helminth extracts that suppress maturation and IL-12 production from DCs until pure fractions are obtained. The glycan moieties will be analyzed by a combination of mass-spectrometry, glycosidase treatments and linkage analysis to structurally characterize the anti-inflammatory components. The purified glycan-moieties will be coupled to a protein or lipid carrier and their anti-inflammatory properties further evaluated in functional assays using isolated lamina propria and peripheral blood mononuclear cells from patients with IBD, and in vivo in a murine model of experimental colitis.
While it is clear that glycan structures can interact with immune cells and modulate their function, the structural requirements of glycans to modulate inflammatory responses, and the molecular mechanisms involved, are largely unknown. Our proposal is interdisciplinary and highly innovative because we use unique glycochemical approaches to investigate functional pathways within DCs at a molecular level, and translate the obtained knowledge to develop an improved and safe therapy for IBD.
The results of these studies will have a great impact on our general understanding of the immune mechanisms that modulate inflammatory responses. Most importantly, these studies may lead to the development of a safe and effective therapy for the treatment of IBD, and possibly other Th1-based inflammatory diseases.