Inhibition of herpes simplex virus growth caused by preparations of animal immunoglobulins is not dependent on Fc-Fc receptor interactions.

Rabbit, horse, rat, and chicken immunoglobulin G (IgG); rabbit, horse, and goat IgG Fc fragments; rabbit and chicken F(ab')2 fragments, and rat and chicken gamma globulins, in concentrations of 5 and 10 mg/ml, were able to reduce virus production 10- to 10,000-fold when incubated with herpes simplex virus type 1 (HSV-1)-infected GMK AH1 cells. When the ability of the purified IgGs and gamma globulins to interact with the HSV-induced Fc receptor on infected GMK cells was tested, only rabbit IgG and IgG Fc fragments from rabbit and goat were reactive. Thus, there was no correlation between the ability to interact with the HSV Fc receptor and the ability to inhibit viral growth. The ability of IgGs and gamma globulins to reduce HSV production is, therefore, not likely to be mediated by the HSV Fc receptor.