Comparative Glycomics of Selected Nematodes

Nematodes, unsegmented roundworms, have adapted to various ecological niches through millions of years of evolution. Many members of these organisms are parasites either of humans, vertebrates, invertebrates or plants whereas some nematode species have established a free-living lifestyle. Within the roundworm phylum, parasitism has evolved several times independently and now parasitic members can be found in four out of five clades. Oesophagostomum dentatum, the porcine nodular worm within clade V of the nematode phylum, will be the focus of this study as a model for the strongylids, important parasites of mammals and amongst the closest relatives of Caenorhabditis elegans. The parasite`s surface is adapted to resist the host`s immune system, preventing protective immunity of the host and is known to be a major source for glycoproteins. In this project, the N-glycan epitopes, decorations on the surface of proteins, will be analysed in terms of a differential presentation during the development of Oesophagostomum dentatum. The specific N-glycan epitopes of the invasive third (L3) and the parasitic fourth (L4) larval stages and their excretory/secretory products as well as the gender-specific epitope distribution of the gut-inhabiting adults will be examined in detail using immunochemical, chromatographic and mass spectrometric techniques. In comparison to its closely-related free-living relatives, such as the model organism Caenorhabditis elegans as well as Caenorhabditis briggsae, Caenorhabditis remanei, Caenorhabditis japonica and Pristionchus pacificus, epitopes supporting the parasitic life style will be defined. This study will constitute a basis for an improved understanding of the immunogenic and immunomodulatory glycans of nematodes.

Nematodes, unsegmented roundworms, have adapted to various ecological niches through millions of years of evolution. Many members of these organisms are parasites either of humans, vertebrates, invertebrates or plants whereas some nematode species have established a free-living lifestyle. Within the roundworm phylum, parasitism has evolved several times independently and now parasitic members can be found in four out of five clades. Oesophagostomum dentatum, the porcine nodular worm within clade V of the nematode phylum, was the focus of this study as a model for the strongylids, important parasites of mammals and amongst the closest relatives of Caenorhabditis elegans. The parasites surface is adapted to resist the hosts immune system, preventing protective immunity of the host and is known to be a major source for glycoproteins. In this project, the N-glycan epitopes, decorations on the surface of proteins, were analysed in terms of a differential presentation during the development of Oesophagostomum dentatum. The specific N-glycan epitopes of the invasive third (L3) and the parasitic fourth (L4) larval stages as well as the gender-specific epitope distribution of the gut-inhabiting adults were examined in detail using chromatographic and mass spectrometric techniques. In comparison to its closely-related free-living relatives, such as the model organism Caenorhabditis elegans and Pristionchus pacificus, as well as the parasite Trichuris suis various glycan epitopes were defined. This study therefore constitutes a basis for an improved understanding of the immunogenic and immunomodulatory glycans of nematodes.