Anti-Envelope protein [5A]

Absolute Antibody

Anti-Envelope protein [5A]

9

The antibody recognises a quaternary epitope on the envelope protein. The antibody does not bind to E proteins of ZIKV, DENV, or WNV.

The specificity of the scFv format of the antibody was confirmed by ELISA analysis. The antibody showed 50% and 100% neutralizing activity in plaque reduction neutralization assay (PRNT) using Vero cells against YFV strains 17D-204-WHO and Asibi at concentrations of approximately 1 microg/ml and 10 microg/ml, respectively. The antibody neutralized wild-type YFV strains of genotypes West Africa I (Nigeria 1987) and II (Asibi) and East/Central Africa (CAR 1986, Ethiopia 1961) with comparable efficiency in a PRNT on PS cells. Competitive ELISA showed that the scFv fragment competed for binding to YFV-17D virions with Ab02826. An immunoprecipitation assay with radiolabeled, purified YFV-17D virions was performed. The scFv fragment was found to precipitate a 55-kDa protein, corresponding to the molecular weight of the envelope glycoprotein (Daffis et al., 2005; PMID: 15919103). The structure of the scFv fragment of the antibody in complex with the E protein was determined. Surface plasmon resonance (SPR) experiments showed that the antibody bound to sE proteins from both YFV-17D and YFV-China with high affinities (KD values are 13.5 nM and 9.7 nM, respectively). The in vitro neutralizing activity for YFV was assessed using a modified fluorescence-activated cell sorting (FACS)-based assay in Vero cells. The antibody displayed extremely high neutralization activity against both YFV strains (IC50, 15 ng/mL and 6 ng/mL for YFV-China and YFV-17D, respectively). Mice treated with the antibody were completely protected against YFV-17D infection. Pre- and post-attachment neutralization assays were carried out in BHK-21 cells. In both cases the antibody efficiently neutralized the virus ((IC50= 19 ng/mL and IC50= 8 ng/mL respectively). Finally, the antibody partially blocked pH-dependent fusion of YFV-17D with liposomes (IC50, 19 ng/mL) (Lu et al., 2019).

Functional Assay, ImmunoPrecipitation, ELISA, Neutralisation/Blocking, Other Application

Research Use Only

Monoclonal

5A

POLY

polyprotein

polyprotein; YFVgp1

Genome polyprotein

Virus

-20°C,2°C to 8°C

12352203