Summary: | <p>Abstract</p> <p>Background</p> <p>Studies of the host response to infection often require quantitative measurement of the antiviral type I interferons (IFN-α/β) in biological samples. The amount of IFN is either determined via its ability to suppress a sensitive indicator virus, by an IFN-responding reporter cell line, or by ELISA. These assays however are either time-consuming and lack convenient readouts, or they are rather insensitive and restricted to IFN from a particular host species.</p> <p>Results</p> <p>An IFN-sensitive, <it>Renilla </it>luciferase-expressing Rift Valley fever virus (RVFV-Ren) was generated using reverse genetics. Human, murine and avian cells were tested for their susceptibility to RVFV-Ren after treatment with species-specific IFNs. RVFV-Ren was able to infect cells of all three species, and IFN-mediated inhibition of viral reporter activity occurred in a dose-dependent manner. The sensitivity limit was found to be 1 U/ml IFN, and comparison with a standard curve allowed to determine the activity of an unknown sample.</p> <p>Conclusions</p> <p>RVFV-Ren replicates in cells of several species and is highly sensitive to pre-treatment with IFN. These properties allowed the development of a rapid, sensitive, and species-independent antiviral assay with a convenient luciferase-based readout.</p>
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