title: Inhibition by rheumatoid factor, anti-FC, and staphylococcal protein A of antibody-dependent cell-mediated cytolysis against Herpes simplex virus-infected cells.
abstract: Incubation of herpes simplex virus-infected human fibroblasts with the serum from a patient with herpes labialis rendered the cells susceptible to immune lysis by human mononuclear leukocytes (MNL) as well as complement. If, before the addition of MNL, the antibody-treated, infected monolayers were incubated with either IgM rheumatoid factor (RF), staphylococcal protein A (SPA), or anti-Fc gamma serum, antibody-dependent cell-mediated cytolysis (ADCC) was markedly depressed. SPA and anti-Fc caused maximal inhibition (greater than 90%), whereas RF resulted in a 72% depression. The inhibition of ADCC was dependent on both the concentration of the Fc-reacting materials incubated with the antibody-coated target cells and the concentration of antiviral antibody incubated with the virus-infected fibroblasts. Experiments indicated that the Fc-reacting materials depressed ADCC at the target cell level by covering or altering Fc sites on cell-bound antiviral antibody.
mesh_terms: D000888:Antibodies, Anti-Idiotypic; D000914:Antibodies, Viral; D001426:Bacterial Proteins / Q000494:pharmacology*; D005347:Fibroblasts / Q000276:immunology*; D006801:Humans; D007111:Immunity, Cellular; D007141:Immunoglobulin Fc Fragments; D007165:Immunosuppression Therapy; D012217:Rheumatoid Factor / Q000494:pharmacology*; D018139:Simplexvirus / Q000276:immunology*; D013210:Staphylococcus / Q000276:immunology
chemical_list: D000888:Antibodies, Anti-Idiotypic; D000914:Antibodies, Viral; D001426:Bacterial Proteins; D007141:Immunoglobulin Fc Fragments; D012217:Rheumatoid Factor