3.5 Application of pseudotyped EBOV-based neutralization assay
Three samples of antibody-based reagents against EBOV (immunoglobulin
fragments, lyophilized IgG, equine antisera) were evaluated in
vitro using the pseudotyped EBOV-based neutralization assay. As shown
in Fig. 3b, the neutralization efficiency of all samples correlated with
serially diluted concentrations, and a linear relationship was
confirmed. The NT50 and NT90 of the
three samples are shown in Fig. 3c and 3d. The results revealed that all
samples showed high neutralization activity to the EBOV pseudotyped
virus. We concluded that the pseudotyped EBOV-based neutralization assay
was sufficiently reliable to evaluate neutralizing antibody titers of
different samples.
To show the relationship between IgG and neutralizing antibody against
EBOV, we further compared the results of the pseudotyped EBOV-based
neutralization assay and an indirect ELISA. As shown in Table 1, the
neutralizing antibody titers varied with the IgG titers detected by
indirect ELISA, and a correlation between the results of the two assays
was identified, suggesting the validity and reliability of the results
detected by the pseudotyped EBOV-based neutralization assay.