A solid-phase assay of solubilized HeLa cell membrane receptors for binding group B coxsackieviruses and polioviruses

HeLa cell membranes were solubilized in sodium deoxycholate and adsorbed onto polystyrene microtiter plates to permit the measurement of receptors for binding group B Coxsackieviruses and polioviruses. Receptor activity was determined by measuring the amount of infectious virus attached to coated wells at 6°. Conditions for optimal binding of virus were determined. Receptor binding activity for group B Coxsackieviruses was detected from as few as 2.5 × 10⁴ cell equivalents/ml to provide a method which was over 400 times more sensitive than the virus eclipse assay used previously. The assay revealed a recovery of up to 7% of the receptor activity of whole cells based on virus saturation of receptors. The specificity of the binding activity of the immobilized receptors was demonstrated by virus attachment competition, as done previously for receptors on live HeLa cells. Application of this method to measure receptors in deoxycholate-solubilized fetal mouse brain revealed a 2500-fold increase in sensitivity from that obtained in a virus-binding assay used previously.