United Kingdom (UK)
Recombinant monoclonal antibody to Envelope protein. Manufactured using AbAb’s Recombinant Platform with variable regions (i.e. specificity) from the phage display antibody 5A.
UniProt Accession Number of Target Protein: P03314
Alternative Name(s) of Target: E protein; Envelope protein E; Genome polyprotein
Immunogen: The original antibody was generated by phage display method. Two antibody-phage libraries were constructed by repertoire cloning from yellow fever patients, subsequently pooled and panned with glycerol-purified non-inactivated YFV-17D virions.
Specificity: The antibody recognises a quaternary epitope on the envelope protein. The antibody does not bind to E proteins of ZIKV, DENV, or WNV.
Application Notes: 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 µg/ml and 10 µg/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).
Antibody first published in:
Daffis et al. Antibody responses against wild-type yellow fever virus and the 17D
vaccine strain: Characterization with human monoclonal antibody
fragments and neutralization escape variants Virology. 2005 Jul 5;337(2):262-72. PMID:15919103
Note on publication:
Describes the generation, characterization and neutralizing capabilities of this antibody.