title: Using label-free proteomics to elucidate factors involved in the human response to orthohantavirus infection
Creators: name: Bar-Yaacov, SB
Publisher: name: University of Liverpool Repository
Year: 2019

description: Orthohantaviruses are a genus of Bunyaviruses carried by a range of rodent hosts. They are found in endemic foci across the globe and are associated with the zoonotic diseases haemorrhagic fever with renal syndrome and hantavirus cardiopulmonary syndrome. Orthohantaviruses are enzootic to south-eastern, central and northern parts of continental Europe. The virus has historically been considered absent from the British Isles, but the endemic presence of Seoul orthohantavirus (SEOV) was demonstrated in wild and pet rats in the UK in 2012. For the last six years several human cases of orthohantavirus-infections have been diagnosed in the UK with associated acute renal failure. Currently, treatment for haemorrhagic fever with renal syndrome and hantavirus cardiopulmonary syndrome is purely symptomatic. The mechanisms underlying the pathogenesis of orthohantavirus infections are not fully understood though several lines of enquiry have demonstrated the multifaceted nature of the disease, with direct virally mediated mechanisms, indirect immune mediate mechanism and genetic host factors all likely contributors to the clinical picture. Clinical proteomics is a field of study in which high-throughput analytical approaches are used to investigate proteins in clinical samples. A major advantage of the proteomic approach is that no a priori knowledge is required for proteome analysis, making it an excellent hypothesis generating experimental method. The high-throughput facets of proteomic methods also make the approach very useful for infections such as orthohantavirus, for which aspects of its pathology remains unclear, and the relative rarity of the associated diseases result in limited access to biological samples. The aims of this study were to use label-free proteomics to discover biomarkers of orthohantavirus infection in clinical human sera and to study the cellular interactome of recombinant SEOV Cherwell glycoproteins in a human kidney cell line, with the objective of gaining further insights into mechanism involved in the processing of viral proteins through host cells. A pipeline for investigating the human serum proteome during diseased and healthy conditions was established. Using label-free proteomics in association with immunological methods, afamin and galectin 3-binding protein were identified and evaluated as putative biomarkers of orthohantavirus infection. Both proteins showed promise as factors involved in the response to acute Seoul orthohantavirus infection. Their relevance as markers of disease were supported by their functional annotation, with afamin playing a possible role in the cellular response to oxidative stress, and galectin 3-binding protein being associated with pro-inflammatory and pro-coagulant activity. Further validation studies with larger sample cohorts are warranted. Initial investigations into the in vitro interactome of recombinant SEOV Cherwell glycoproteins identified 12 potential associations between host and viral proteins. While functional analysis of selected proteins revealed a potential for relevance in the viral life cycle, further follow-up of these findings will be required to establish whether the identified associations are firstly, true associations, and secondly, biologically relevant interactions.