Effects of some components of the humoral immune response on the replication of bovine herpesvirus type I in tracheal organ cultures

The addition of high concentrations of serum neutralizing antibody against bovine herpesvirus type I (BHV-1) to bovine fetal tracheal organ cultures before and after infection with a minimal infectious dose of BHV-1 completely inhibited virus replication. The daily addition of serum antibody from day 0 to day 2 after infection markedly reduced virus yields but failed to cure the infection. The antiviral effect of nasal antibody was not superior to that of an equivalent concentration of serum antibody. Treatment of infected organ cultures with complement sometimes enhanced the antiviral effect of antibody. Peripheral blood lymphocytes from an experimentally infected calf were cultivated in the presence of BHV-1 antigen, and the culture supernatants were shown to possess interferon activity. Pretreatment of organ cultures with this material failed to inhibit BHV-1 replication, but when the interferon treatment was continued daily after infection, there was a transient reduction in BHV-1 replication.