Flaviviruses constitute an increasing source of public health concern, with growing numbers of pathogens causing disease and geographic spread to temperate climates. Despite a large body of evidence supporting mutagenesis as a conceivable antiviral strategy, there are currently no data on the sensitivity to increased mutagenesis for Zika virus (ZIKV) and Usutu virus (USUV), two emerging flaviviral threats.

The cytokine tumour necrosis factor α (TNF-α) has been shown to play a role in human immunodeficiency virus (HIV) replication by activating transcription of the provirus in both T cells and macrophages. Therefore, agents that block TNF-α-induced HIV expression could have therapeutic value in the treatment of AIDS. We have sought to identify antiviral agents that block TNF-α induction of HIV LTR-directed transcription, using a cell-based, virus-free assay system in automated high-throughput screening. HeLa cells were transfected with an HIV LTR-luciferase reporter plasmid and a stable line was isolated in which TNF-α increased luciferase production by two-to threefold. This cell line was used to screen approx-