Generation and Selection of a Panel of Pan-Filovirus Single-Chain Antibodies using Cell-Free Ribosome Display

Abstract

Filoviruses, which include ebolaviruses and marburgvirus, can cause outbreaks of highly lethal hemorrhagic fever. This disease causes significant morbidity and mortality in humans and nonhuman primates, with human fatality rates reaching 90% during some outbreaks. Currently, there are a lack of licensed vaccines or antivirals for these viruses. Since early symptoms of filovirus infection mimic more common diseases, there is a strong unmet public health and biodefense need for broad-spectrum filovirus rapid diagnostics. We have generated a panel of mouse single-chain Fv-antibodies (scFvs) to filovirus glycoproteins (GPs) using cell-free ribosome display and determined their cross-reactivity profiles to all known filovirus species. Two scFvs (4-2 and 22-1)were able to detect all known Ebolavirus and Marburgvirus species. This is the first report on ribosome display scFvs that can detect a broad set of filovirus GPs, which demonstrates their potential use in the development of a new generation of rapid diagnostic immunoassays. Author summaryFiloviruses, such as Ebola virus, cause severe and often fatal hemorrhagic fever in humans. The current Ebola virus outbreak is a health crisis with global repercussions and underscores the need for rapid and inexpensive diagnostics to detect filovirus infection. For these reasons, we used a ribosomal display method to rapidly generate single-chain antibodies (scFv's) for use in diagnostics against all six pathogenic filoviruses from mice immunized with EBOV virus-like particles (VLPs). We have successfully isolated two scFvs that can detect all known Ebolavirus and Marburgvirus species using this method. This method is inexpensive, rapid, and can be used to quickly develop repertoires of high-affinity antibodies for detection of a broad set of filovirus GPs.