Novel neutralizing monoclonal antibodies protect rodents against lethal filovirus challenges

Filoviruses are the causative agents of lethal hemorrhagic fever in human and non-human primates (NHP). The family of Filoviridae is composed of three genera, Ebolavirus, Marburgvirus and Cuevavirus. There are currently no approved vaccines or antiviral therapeutics for the treatment of filovirus infections in humans. Passive transfer of neutralizing antibodies targeting the Ebola virus (EBOV) glycoprotein (GP) has proven effective in protecting mice, guinea pigs and NHP from lethal challenges with EBOV. In this study, we generated two neutralizing monoclonal antibodies (MAbs), termed S9 and M4 that recognize the GP of EBOV or multiple strains of Marburg virus (MARV), respectively. We characterized the putative binding site of S9 as a linear epitope on the glycan cap of the GP1 subunit of the EBOV-GP. The M4 antibody recognizes an unknown conformational epitope on MARV-GP. Additionally, we demonstrated the post-exposure protection potential of these antibodies in both the mouse and guinea pig models of filovirus infection. These data indicate that MAbs S9 and M4 would be good candidates for inclusion in an antibody cocktail for the treatment of filovirus infections