Selection and characterization of highly specific recombinant antibodies against West Nile Virus E protein.

West Nile virus is a widespread mosquito-borne human and animal pathogenic virus of increasing importance. The E protein of the viral envelope is critical for attachment and entry into the host cell and has been the target for vaccine design and small molecule inhibitors. Furthermore, the detection of anti-E IgM and IgG antibodies is widely used in serology to diagnose these infections. Here we describe a strategy for the production of recombinant antibodies against the E protein of West Nile virus for research and immunodiagnostic purposes. Initially the fast and easy protocol previously developed for the similar Tick-borne encephalitis virus has been adapted to West Nile virus E antigen production and purification. A human naïve scFv phage library has been selected on the produced antigen, identifying a panel of highly specific anti-E protein antibodies. Once produced as scFv-Fc recombinant proteins, the selected antibodies have been characterized by mapping their binding sites and by defining their affinity for the target. The impact on neutralizing virus attachment and entry has been also evaluated. The obtained results demonstrate the potential of the produced reagents for research and diagnostic applications.