Use this URL to cite or link to this record in EThOS:
Title: In vitro analysis of viral fusion and receptor binding with a focus on selected arthropod-borne viruses of the families Bunyaviridae and Togaviridae
Author: Bitto, David
ISNI:       0000 0004 5355 1279
Awarding Body: University of Oxford
Current Institution: University of Oxford
Date of Award: 2014
Availability of Full Text:
Access from EThOS:
Full text unavailable from EThOS. Restricted access.
Access from Institution:
Emerging arthropod-borne viruses, such as alphaviruses and bunyaviruses, represent a serious threat to human and animal health worldwide, and for most of them, vaccines and specific treatments are unavailable. Viral host cell entry can be divided into several entry checkpoints, and the most important checkpoints for low pH-dependent enveloped viruses, such as bunyaviruses and alphaviruses, include receptor binding at the cell surface and, followed by endocytosis, low pH dependent membrane fusion from within intracellular compartments. A more thorough understanding of the detailed mechanisms allowing the viruses to pass these checkpoints is a pre-requisite for the design of viral entry inhibitors. This thesis reports the in vitro analysis of native alphavirus-receptor interactions, with the help of electron cryo-microscopy and icosahedral reconstruction of virus-recaptor complexes, using the prototypic alphavirus Semliki Forest virus (SFV) and the C-type lectin DC-SIGN. Together with results from collaborative work on SFV glycosylation, this study provides progress in defining the binding sites of DC-SIGN at the surface of SFV. Second, an in vitro system for phlebovirus fusion was developed using standard fluorometry, and has been characterized with the help of electron cryo-microscopy. It was discovered that negatively charged phospholipids with a conical shape, including the late endosomal phospholipid BMP, allow efficient phlebovirus fusion in vitro, thereby providing a possible rationale for phlebovirus fusion in late endosomes. Furthermore, electron cryo-microscopy of phlebovirus-liposome complexes allowed the capture of early stage fusion intermediates and laid the basis for possible future higher resolution studies of these fusion intermediates.
Supervisor: Huiskonen, Juha T.; Gruenewald, Kay Sponsor: Academy of Finland
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: Life Sciences ; Medical sciences ; Viruses ; Infectious diseases ; Biochemistry ; Virus entry ; Bunyaviridae ; Phlebovirus ; Uukuniemi virus ; Alphavirus ; Semliki Forest virus ; Membrane fusion ; Electron cryomicroscopy ; Electron cryotomography ; Icosahedral reconstruction