Enzyme Immunoassay of Interferon with Peroxidase-labelled Virus-specific Monoclonal Antibodies

Abstract

SUMMARYTo quantify the antiviral effect of interferon (IFN) we applied a mixture of two horseradish peroxidase-labelled monoclonal antibodies, specific for the E1 glycoprotein of Semliki Forest virus, in a direct enzyme immunoassay. This assay is suitable for detection of virus replication in L-cells, seeded as monolayers in 96-well plates. Inhibition of absorbance values caused by IFN was determined in a Flow Titertek Multiskan. Three IFN samples from different sources were titrated simultaneously in the enzyme immunoassay and in the vesicular stomatitis virus plaque reduction test in five consecutive experiments. Titres were calculated as the inverse value of the dilution of IFN causing 25~ inhibition of absorbance values and 50~ reduction of plaque counts respectively. The results show equality of precision and reproducibility between and within-the two assays. However, the enzyme immunoassay is more convenient and objective than the plaque reduction assay.Many methods for assessing the antiviral effects of interferon (IFN) have been described

Rapid determination of neutralizing antibodies to Semliki Forest virus in serum by enzyme immunoassay in cell culture with virus-specific monoclonal antibodies

“…Previously, we described an EIA that used horseradish peroxidase-labeled MAbs directed against either the El or E2 glycoprotein of SFV to detect SFV on L-cell monolayers (19). This test was successfully adapted to quantify the suppressive action on viral replication of interferon or antiviral agents like ribavirin (17,20). The present study shows that the test can also be used for the reliable determination of neutralizing antibodies in mouse serum to SFV.…”

“…These viral glycoproteins on the surface of infected L-cell monolayers could be quantified with labeled MAbs. The EIA was adapted to quantify the antiviral effect of interferon (17) and to determine inhibitory concentrations of antiviral agents in cell cultures (18).…”

“…The horseradish peroxidaseconjugated MAb UM 5.1 diluted to 1:30,000 was then added (0.05 ml per well) and the plates were incubated for 1 h at 37°C. The EIA was performed further as described in earlier papers (17,19). The results of both tests are presented in Fig.…”