CHARACTERIZATION OF HERPES-SIMPLEX VIRUS TYPE-1-INDUCED FC RECEPTOR IN ITS INTERACTION WITH RABBIT IMMUNOGLOBULIN-G (IGG)

Herpes simplex virus (HSV) induces a receptor on infected cells that is able to bind the Fc part of immunoglobulin G (IgG). We have examined some basic physicochemical and binding properties of the Fc receptor induced on HSV-1 infected green monkey kidney (GMK) cells in its interaction wiht rabbit IgG. Fixation of HSV-1 infected cells with glutaraldehyde, formaldehyde, acetone or ethanol did not inhibit the Fc binding ability. The binding specificity of the receptor was not affected by ethanol treatment and all subsequent binding studies were performed with cells treated with ethanol. The receptor was detected within 4 hours of infection and the binding increased until 16 hours post infection. The interaction between ligand and receptor was dependent on pH with a binding optimum around pH 8.0 and 8.5. EDTA, but not EGTA, inhibited receptor binding, suggesting participation of divalent cations in the receptor-ligand interaction. Inhibition of binding was also seen when cells were preincubated for 30 min at 56°, 60° and 100 °C in contrast with cells incubated at 37° and 45°C. The number of binding sites on ethanol-treated GMK cells 18 hours after infection was estimated to be around 4 x 106/cell and the affinity constant at approximately 2 x 107M-1.