A rapid and sensitive micro scale assay for quantitative detection of cell protective effects: application for the isolation of a monoclonal antibody against HeLa cell proteins involved in poliovirus attachment.

A combined assay consisting of a pre-cpe-protection assay and a double-antibody sandwich ELISA for detecting poliovirus was developed on a microtiter scale in order to quantify inhibition of virus replication caused by cell protective antibodies. The system was of high sensitivity and allowed the measurement of the protecting effect caused by a broad range of antibody concentrations before appearance of cytopathic effects. It was applied as a screening test for a large number of hybridomas secreting antibodies specific to the surface of HeLa cells and allowed the identification of four monoclonal antibodies (mAbs) with partial protection activity against poliovirus infection. One of the antibodies, mAb 122, detected SDS-PAGE-separated HeLa cell membrane proteins of 23-25 kDa and 50 kDa by immunoblot, indicating that these proteins are involved in poliovirus adsorption.