Neutralizing antibody to herpes simplex virus by a novel neutralization method with peroxidase-labelled complement Clq

Abstract

A theoretically new neutralization method was developed for rapid and quantitative detection of virus neutralizing antibodies. The method involves the specific measurement of viral antigens produced by unneutralized virus by antiviral immune serum and peroxidase-labelled complement Clq (P*-Clq). After incubation of 37 degrees C for 18 h for amplification of herpes simplex virus (HSV) as a model, to detect unneutralized HSV, the amounts of HSV antigens produced in cells are measured by OD reading of enzymatic activities of P*-Clq bound to the HSV antigen-antibody complex formed after addition of anti-HSV probe serum and P*-Clq. Results showed that the OD reading of bound P*-Clq was proportional to the input m.o.i. of HSV and that neutralization of HSV with immune serum or human sera resulted in significant reduction of HSV-specific OD readings, depending on the antibody titers of serum samples used. The neutralizing antibody activity can be expressed as a percentage (NT%) of the quantity of neutralized virus, and the entire assay procedure can be completed within 24 h. This new method can replace the conventional neutralization test.