An insertion in the caprine IRF3 gene affects macrophage response to B. melitensis infection

Abstract

Brucella melitensis is the etiological agent of brucellosis in goats and the main cause of human brucellosis. Interferons (IFNs) are important cytokines in the immune responses to intracellular pathogens and tumor cells. Although IFNβ is classically associated with antiviral responses, growing evidence shows that IFNβ is also involved in the cellular response to bacterial infections. IRF3 is a member of the interferon regulatory transcription factor family that plays a critical role in both the early and late phases of the IFNα/β gene induction. In general, it is considered that IRF3 acts as a suppressor of pro-inflammatory genes and an enhancer of anti inflammatory genes. For example, IRF3 can be directly recruited to the IL12B promoter suppressing its expression. It was reported that B. abortus induces IFNβ expression in an IRF3-dependent manner, and that mice lacking the IFNα/β receptor are more resistant to Brucella infection.