Cell-based assays to identify inhibitors of viral disease

Background: Antagonizing the production of infectious viruses inside cells requires drugs that can cross the cell membrane without harming the host cells. Objective: It is therefore advantageous to establish the intracellular potency of antiviral drug candidates early in the drug discovery pipeline. Methods: To this end, cell-based assays are being developed and used in high-throughput drug screening, ranging from assays that monitor replication of intact viruses to those that monitor activity of specific viral proteins. Although numerous cell-based assays have been developed and investigated, rapid counter screens are also needed to define the specific viral targets of identified inhibitors and to eliminate non-specific screening hits. Results/conclusions: Here, we describe the types of cell-based assays being used in antiviral drug screens and evaluate the equally important counter screens that are being used to reach the full potential of cell-based high-throughput screening.