Detection of herpesvirus antigens by solid-phase radioimmunoassay with 125I-antiglobulin and 125I-protein A.

The binding of immune (IS) and non-immune (NS) sera to herpes simplex virus type 1- (HSV-1) infected Vero cells was tested by indirect solid-phase radioimmunoassay (RIA) with radioiodinated swine anti-rabbit IgG (125I-SwAR-IgG) or staphylococcal protein A (125I-SPA). To indicate the binding of non-immune IgG molecules to virus-induced Fc-receptors, the cells were incubated in the presence or absence of the glycosylation inhibitor 2-deoxy-D-glucose (DOG). With 125I-SwAR-IgG, the binding of both IS and NS to untreated cells was higher at all time intervals than their binding to infected cells kept post infection in the presence of DOG. The titre of IS as detected by 125I-SwAR-IgG remained unchanged regardless whether the cells were incubated in the presence or absence of the drug. 125I-SPA gave much higher net binding than 125I-SwAR-IgG but, the end point titre of IS as measured by 125I-SPA was 1-2 dilution steps lower than with 125I-SwAR-IgG.