Fig 1.
Screening strategies for studying later stages of viral infections and avoiding rediscoveries.
(A) Pseudotyped viruses bypass host factors affecting canonical attachment and entry events. (B) FACS-based selection of reporter genes (such as GFP shown here) or endogenous viral protein expression studies noncytolytic pathogens or specific timepoints postinfection and does not rely on cell survival as a phenotype. (C) Meta-analysis increases statistical power and reprioritizes hits by combining data from multiple studies or different systems-level techniques. (D) Regulatable screening platforms manipulate host genes at defined time points to query discrete stages of the viral life cycle, as exemplified by the dox-inducible CRISPRa system shown here. Light-inducible, cleavage-activated, and complementation-based regulation strategies also exist. (E) Virus-driven selections are possible when the virus itself alters endogenous host genes postinfection (for example, by using a virally encoded miRNA to repress a target transcript). The effect of these alterations will alter the replication fitness of the encoding virus, changing its abundance over the course of replication. CRISPRa, CRISPR activation; FACS, fluorescence-activated cell sorting; GFP, green fluorescent protein; miRNA, microRNA.