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.