Neutrophils in antiviral immunity: inhibition of virus replication by a mediator produced by bovine neutrophils.

Neutrophils collected from bovine mammary glands were placed in culture with virus-infected cell preparations that had been inactivated by ultraviolet light. Upon culture with infectious bovine rhinotracheitis (IBR) virus-infected Georgia bovine kidney cells, a material was released from the neutrophils that, like interferon, inhibited the replication of vesicular stomatitis virus and IBR virus. Cell-free IBR virus was a less effective inducer of the inhibitor produced by neutrophils. Other herpesviruses (including herpes simplex type 1), as well as equine rhinopneumonitis virus and pseudorabies virus, caused release of the inhibitor, but most other viruses tested, including Newcastle disease virus, a good inducer of type 1 interferon, failed to stimulate the production of inhibitor by polymorphonuclear neutrophils. Preliminary characterization studies revealed differences between the inhibitor produced by the polymorphonuclear neutrophils and type 1 and type II bovine interferons. The possible role of such an inhibitor in the recovery from herpesvirus infection is briefly discussed.