Poster Presentation HUPO 2019 - 18th Human Proteome Organization World Congress

Discovering the N-linked glycome of the important zoonotic parasite Fasciola (#872)

Jaclyn Swan 1 , Kim Johnson 1 , Tony Bacic 1 , Travis Beddoe 1
  1. Animal, plant and soil sciences , La Trobe University, Bundoora, Victoria , Australia

Fasciola hepatica is a globally distributed zoonotic parasite which causes a large economic impact on the agricultural sector and human health. Due to the increasing prevalence of drug resistance, alternative treatment methods are urgently required. Many protein antigens have been trialled as vaccine candidates, with promising but variable success. It has been a common observation that native vaccines have far more efficacy than their recombinant orthologues and this is likely due to altered post-translational modifications with the recombinant proteins. The tegument of the parasite, which comes in direct contact with the host immune system, is highly glycosylated and a major source of potential vaccine antigens.  Hence, glycosylation patterns of F. hepatica glycoproteins warrant further investigation. To better predict potential glycan structures that may be present, in silico methods have been used to identify potential glycosyltransferases that are present in F. hepatica and the closely related species F. gigantica. This has demonstrated many similarities between the two species, as well as highlighting a novel xylosyltransferase not previously known to exist in Fasciola spp. It is known that N-glycan structures can be quite heterogenic, and therefore to understand if this occurs in F. hepatica, we have used hydrophilic interaction liquid chromatography followed by high-resolution tandem mass spectrometry with complementary and triggered fragmentation to reveal a number of glycoproteins containing a range of N-glycans. The majority of these N-glycans have an oligomannose or paucimannose structure. These N-glycans possibly play a role in host recognition and/or protein folding. This information will provide insight into the natural occurrence of N-glycan heterogeneity on F. hepatica glycoproteins providing new information that can be considered when engineering a recombinant expression system for potential vaccine candidates in the future.