EASTBIO: Gut-parasite interactions in African trypanosome infections

Supervisors:

Dr Jeremy Sternberg (University of Aberdeen) https://www.abdn.ac.uk/staffnet/profiles/jsternberg/

Professor Neil A Mabbott (The Roslin Institute, University of Edinburgh) http://www.ed.ac.uk/roslin/about/contact-us/staff/neil-mabbott

Dr Liam Morrison (The Roslin Institute, University of Edinburgh) https://www.ed.ac.uk/roslin/about/contact-us/staff/liam-morrison

African trypanosome infections lead to morbidity and death in both humans (human African trypanosomiasis, ca 30,000 cases per year currently) and livestock (loss of productivity in bovine sector alone estimated at 1.2 billion USD/per year). We are interested in definition of the mechanisms driving the type 1 inflammatory responses that plays a key role in pathogenesis, and have recently discovered that clinical disease is associated with endotoxaemia and gut-blood barrier impairment (Maclean, Aboubaker et al. 2017). What is the mechanism of that barrier impairment? It is possible that it is driven by the systemic inflammatory cytokine milieu that develops during infection. Alternatively, it could be a cellular response to parasites in the vasculature or tissues at the basolateral surface of the barrier.
This project aims to address this question and provide a mechanistic basis for endotoxaemia in trypanosome infection. The strategy will be to investigate the interactions in vitro of African trypanosomes with:

(i) the “CaCo2” model of the gut epithelium, which is well established for gut toxicology, pharmacodynamics and barrier function (Sambuy, De Angelis et al. 2005), using physiological and molecular markers of permeability (including that of endotoxins), and adhesion protein expression

(ii) Using intestinal organoids(Sato and Clevers 2013, Hamilton, Young et al. 2018), where barrier function will typically be measured by quantitative confocal fluorescence imaging after microinjection of fluorescence labelled dextran to the luminal cavity. The project will explore the effects of exposure of organoids to trypanosomes, parasite conditioned medium, and inflammatory cytokines at concentrations representative of in vivo infections.

A final strand of this project will allow the student to access a bank of serum samples from Human African trypanosomiasis patients and test the hypothesis that endotoxaemia is directly related to disease outcome. The outcomes of this research will be directly relevant to our understanding of disease development in both livestock and humans and may indicate new therapeutic strategies. The experimental approach will primarily use in vitro models and will thus provide extensive training in both mammalian and protozoal cell-culture, with a range of physiological (eg trans epithelial electrical resistance), immunological (eg immunoassay, immunofluorescent imaging) and molecular (eg q-PCR) assays.