Two new monoclonal antibodies for biochemical and flow cytometric analyses of human interferon regulatory factor-3 activation, turnover, and depletion

Interferon regulatory factor-3 (IRF-3) is a master transcription factor that drives the host intracellular innate immune response to virus infection. The importance of IRF-3 in innate immune responses is highlighted by the fact that pathogenic viruses have developed strategies for antagonism of IRF-3. Several tools exist for evaluation of viral regulation of IRF-3 activation and function, but high-quality monoclonal antibodies that mark the differential activation states of human IRF-3 are lacking. To study IRF-3 activation, turnover, and depletion in a high-throughput manner in the context of virus infection, we have developed two new monoclonal antibodies to human IRF-3. These antibodies detect IRF-3 in virus-infected cells in a wide variety of assays and provide a new tool to study virus-host interactions and innate immune signaling.

► We developed two new monoclonal antibodies (mAbs) to human IRF-3: AR-1 and AR-2.
► Both mAbs recognize denatured IRF-3 in its resting and activated isoforms.
► AR-1 prefers active IRF-3 in native conditions and detects non-human primate IRF-3.
► Both mAbs demonstrate utility in assays of IRF-3 antagonism during virus infection.
► We describe a novel flow cytometry assay for measurement of IRF-3 activation.