Figure 3.

Human rhinovirus (HRV)-16-induced interferon-stimulated gene of 15 kDa (ISG15) expression is controlled at the level of transcription. A 634-bp ISG15 promoter sequence and various truncated forms were cloned upstream into a pGL4.10 firefly luciferase plasmid and transiently transfected into BEAS-2B cells using lipid-mediated techniques. Cells were exposed to medium (M) or infected with HRV-16 (V) for 24 h and luciferase activity was measured. Data are presented as (a) fold increase over medium control and (b) relative light units (RLUs), and represent mean±s.e.m. (n=6). Asterisk indicates significant difference between 634-bp vs. truncated forms in HRV-16-infected cells (P<0.05). Transcription factor binding sites in the ISG15 promoter: CRE, cAMP response element; IRF, interferon regulatory factor; κB, nuclear factor-κB; STAT, signal transducer and activator of transcription.