Possible role of Fc receptors on cells infected and transformed by herpesvirus: escape from immune cytolysis.

Receptors for the Fc portion of nonimmune immunoglobulin G were demonstrated on B103 rat brain neuroma cells infected with herpes simplex virus type 1 (HSV-1) KOS by a radioimmunoassay using 125I-labeled heat-aggregated Fc fragments. Immune F(ab')2 fragments specific for HSV antigens competed efficiently for Fc binding sites, suggesting that the binding of Fc fragments to infected cells is specific for viral cell-surface antigens. It has been suggested that the binding of immune complexes to Fc receptors on the surfaces of tumor cells in vivo plays a role in protecting these cells from immune destruction. In vitro evidence is presented for the ability of aggregated immunoglobulin G molecules bound to cell-surface Fc receptors to protect both HSV-infected and HSV-transformed cells against complement-dependent and cell-mediated immune lysis.