Use of a Discistronic Vector for the Quantitation of HCV IRES Activity

The 5′-untranslated region of hepatitis C virus (HCV) has been shown to function as an internal ribosomal entry site, or IRES. The biological function of the HCV IRES has been shown to be essential for initiation of translation of the viral proteins by host ribosomes. With this critical role in HCV replication, the IRES makes an attractive target for the development of antiviral compounds Furthermore, since eukaryotic translation is not initiated via an IRES, agents that specifically interfere with function of the HCV IRES may be relatively nontoxic to the host Fundamental to the testing of any of these antivirals is a system to evaluate their efficacy. This chapter describes the use of a dicistromc vector in an in vitro system to assess the translational initiation efficiency of isolated HCV IRES elements.