Filoviruses, including members of the Ebolavirus and Marburgvirus genera, are among the most severe threats to global health. Notably, Ebolavirus species such as Ebola virus (EBOV), Sudan virus (SUDV), and Bundibugyo virus (BDBV) have caused highly lethal outbreaks, often characterised by haemorrhagic manifestations and systemic multiorgan dysfunction. Furthermore, a number of divergent filoviruses have recently been described including Měnglà virus (MLAV), which has shown to bind the same host receptor as EBOV, highlighting the potential for spillover. Filovirus presents only one glycoprotein (GP) on the virion surface, a class I fusion protein composed of two disulfide-linked subunits: GP1 and GP2. GP1 contains a core, a glycan cap, and a mucin-like domain (MLD), which mediate attachment to host cells, while GP2 anchors the protein to the membrane and facilitates the fusion of viral and host cell membranes. Antibodies targeting GP have been strongly associated with protection against Ebolavirus infections, making GP a primary target for therapeutic and vaccine development. Although existing vaccines and therapies have demonstrated efficacy against EBOV, they are less effective against other filoviruses. Therefore, the development of broad-spectrum vaccines and treatments targeting multiple pathogenic filovirus species remains an urgent priority.
This work aims to provide a comprehensive biochemical and biophysical characterisation of glycoproteins of filoviruses using a combination of structural-based design, immunological assays, and advanced structural analysis. Ectodomains of both prototypical and diverse filoviruses were cloned, expressed and purified from mammalian cells. Purified proteins were then subsequently analysed for their antigenicity and oligomeric state using size exclusion chromatography. Structural characterisation was further enhanced by transmission electron microscopy to visualise and determine the architecture of the glycoproteins. This research will offer valuable insights into filovirus GP structures and facilitate the antibody discovery and vaccine design against filoviruses.