Figure 7.3.

Phenotypic screening process. Methods to deconvolute the steps in the viral life cycle the hit compounds may be acting upon.

Time of addition of the compounds will determine if compounds are affecting the entry or intracellular replication/spread of the virus. If cells are pretreated with the compound and then infected, then the hit compounds are possibly entry inhibitors. However, if the cells are infected and then treated with the compound, then the compounds may be affecting viral replication and/or budding. To further validate the hits during the various stage of the virus life cycle, surrogate models have been developed such as the use of pseudotype viruses to identify entry inhibitors, minigenome systems to identify hits that modulate virus replications/transcription or the VLPs to identify compounds that disrupt viral assembly/budding. VLP, virus-like particle.