High-throughput screening for small molecule inhibitors of the type-I interferon signaling pathway

Acta Pharm Sin B. 2018 Oct;8(6):889-899. doi: 10.1016/j.apsb.2018.07.005. Epub 2018 Jul 10.

Abstract

Interferons (IFNs) are cytokines with fundamental roles in resistance to infections, cancer and other diseases. Type-I IFNs, interferon α (IFN-α) and interferon β (IFN-β), act through a shared receptor complex (IFNAR) comprised of IFNAR1 and IFNAR2 subunits. Binding of type-I IFN to IFNAR1 will robustly activate Janus activated kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway. Aberrant activation of the type-I IFN response results in a spectrum of disorders called interferonopathies. The purpose of this research is to develop an assay for high-throughput screening (HTS) of small molecule inhibitors of the type-I IFN signaling pathway. Inhibition of type-I IFN signaling can be beneficial in terms of therapeutic use and understanding the underlying mechanism of action. We report here a HTS campaign with the secreted embryonic alkaline phosphatase (SEAP) reporter gene assay against 32,000 compounds which yielded 25 confirmed hits. These compounds were subsequently characterized for their cytotoxicity, effects on STAT phosphorylation and activities in IFN regulatory factor (IRF) transcription.

Keywords: CV, coefficient of variation; DMEM, Dulbecco׳s modified Eagle׳s medium; DMSO, dimethyl sulfoxide; FRET, fluorescence resonance energy transfer; HEK, human embryonic kidney; HTS, high-throughput screening; High-throughput screening; IFN regulatory factor; IFN, interferon; IFNAR, IFN alpha receptor; IRF, IFN regulatory factor; ISGF3, IFN-stimulated gene factor 3; ISRE, IFN-stimulated response element; Inhibitor; Interferon α receptor; JAK, Janus activated kinase; JAK-STAT; S/B, signal to background ratio; SEAP, secreted embryonic alkaline phosphatase; STAT, signal transducer and activator of transcription; Secreted embryonic alkaline phosphatase; TYK, tyrosine kinase; cDNA, complementary DNA; pSTAT, phosphorylated STAT.