Effect of Interferon- , Interferon- and Tumour Necrosis Factor on African Swine Fever Virus Replication in Porcine Monocytes and Macrophages

Summary Bovine interferon-α11 (IFN-α11) and porcine interferon-γ (IFN-γ) inhibited African swine fever virus replication in both porcine monocytes and alveolar macrophages. The most potent antiviral activity was observed with IFN-γ-treated alveolar macrophages. The production of both a virulent (CC83) and a non-virulent (BA71) isolate of the virus was inhibited. Bovine tumour necrosis factor α did not show antiviral activity in either monocytes or alveolar macrophages. Rather, an increase of African swine fever virus production in tumour necrosis factor α-treated monocytes was found. An analysis of viral protein synthesis in IFN-α1l- and IFN-γ-treated alveolar macrophages showed an inhibition of synthesis of some viral proteins. The inhibition of late proteins was very pronounced in IFN-γ-treated cells, and it was probably a consequence of the inhibition of African swine fever virus DNA polymerase activity.