Loss of interferon alpha and interferon tau-induced antiviral protection in interferon regulatory factor-2 DNA-binding domain dominant negative mutants.

ABSTRACT

The role of the interferon regulatory factory (IRF) family of transcription factors in regulation of interferon alpha and interferon tau antiviral activity was investigated using a dominant negative mutant of IRF-2. The IRF-2 DNA binding domain (DBD), without the C-terminal regulatory region, was stably transfected into myeloid U937 cells. Expression of the IRF-2 DBD resulted in an increase in constitutive 2'5' oligoadenylate synthetase (OAS) levels, indicative of an active repressive mechanism, but was not sufficient to protect cells from challenge with vesicular stomatitis virus. Treatment of the DBD clones with interferons alpha A and tau failed to upregulate 2'5' OAS expression and did not elicit an antiviral response. While interferon alpha A was more sensitive than interferon tau to the inhibitory effects of the IRF-2 DBD, IRF-mediated gene induction is involved in successful interferon alpha and tau-induced anti-VSV activity.