Development and characterisation of human monoclonal antibodies against the Ebola virus glycoprotein

The current Ebola virus outbreak in West Africa has infected over 27,000 people and claimed over 11,000 lives, making it the deadliest and most widespread Ebola epidemic in history. The high caseload and rapid geographic spread has been due in part to crumbling healthcare infrastructure, critical shortages of healthcare workers, paucity of resources, and local traditional practices. In addition, although supportive care is available at treatment centres, there are no effective therapies available in the affected countries. A number of potential Ebola virus therapeutic agents are currently being tested in accelerated clinical trials, but there is still no drug with proven efficacy in humans. In this dissertation I describe the isolation of the first fully human Ebola-specific monoclonal antibodies (mAb) from vaccinees during phase 1 of the Oxford Ebola vaccine trial. This was achieved through single cell sorting of antibody secreting cells (ASC) at day seven post boost, isolation of the immunoglobulin (Ig) heavy and light chain genes, expression vector cloning and transfection of human cell lines to produce mAbs. I also attempt to characterise the Ebola-specific mAbâs binding affinity, binding site, and cross-reactivity with other historic Ebola virus strains by enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence assays (IFA). I have also tested their neutralising ability with an in vitro pseudotyped influenza microneutralisation (MN) assay. I present a diverse panel of twelve mAbs with a range of binding characteristics and neutralising abilities, four of which are cross-reactive with both the Zaire and Sudan Ebola viruses. Once fully characterised, these antibodies may potentially be used as part of a mAb cocktail for pre- or post-exposure prophylaxis and cure for Ebola virus disease.