A shared structural solution for neutralizing ebolaviruses

Abstract
The surface glycoprotein of the distinct ebolavirus responsible for the largest outbreak yet described (Sudan Gulu) has been crystallized in complex with a novel, neutralizing antibody. The crystal structure and accompanying in vitro and in vivo experiments demonstrate that the antibody functions after virus entry and illustrates a key hotspot for ebolavirus neutralization. Sudan virus (genus Ebolavirus) is lethal, yet no monoclonal antibody is known to neutralize it. We here describe antibody 16F6 that neutralizes Sudan virus and present its structure bound to the trimeric viral glycoprotein. Unexpectedly, the 16F6 epitope overlaps that of KZ52, the only other antibody against the GP1,2 core to be visualized to date. Furthermore, both antibodies against this crucial epitope bridging GP1–GP2 neutralize at a post-internalization step—probably fusion.