Anti-West Nile Virus (Clone: WNV-86) (LT565-GRP)

West Nile Virus (WNV) is a mosquito-borne, enveloped, positive-stranded RNA flavivirus1. E protein is the main target of flavivirus neutralizing antibodies. E consists of three structural domains (DI, DII, DIII). WNV-86 was generated from peripheral blood mononuclear cells from donors with a history of symptomatic WNV infection1. B cells were transformed with Epstein Barr virus and screened for binding to recombinant soluble WNV E protein. Ten hybridomas were recovered, including WNV-86, which strongly neutralized WNV reporter virus particles (RVP) and completely inhibited fully infectious WNV. WNV-86 is one of the most potently neutralizing flavivirus-specific antibodies ever isolated, neutralizing 50% of virus infectivity at an IC50 of 2 ng/mL. WNV-86 also inhibited infection as a Fab fragment. WNV-86 did not neutralize Dengue or Zika virus. Neutralization escape mutations were generated in Vero cells under WNV-86 selection pressure1. Two amino acid residues in E DII, T64 and T208, individually reduced sensitivity to neutralization and when combined abrogated neutralization. Additionally, a cluster of six mutations in DII that are bound by T64 and T208 reduced neutralization sensitivity by >4 fold, suggesting a binding footprint that partially overlaps with the E binding site of prM. Indeed, virion maturation state affected neutralization. The IC50 of WNV-86 was 4-fold lower against prM- RVPs relative to prM+ RVPs. WNV-86 completely protected mice from mortality when given a single dose post-inoculation1. A LALA variant of WNV-86 that is incapable of engaging Fc receptor gave significant but reduced protection. Both wildtype and LALA WNV-86 reduced viral burden in the spinal cord and brain of infected animals. WNV-86 blocked infection in pre- and post-attachment assays1. WNV-86 is of the IgG1 isotype.