CRISPR screen using pseudotyped viruses identifies specific entry factors for viral infection

To better prepare for future viral outbreaks, scalable and adaptable platforms to study emerging infections are essential. Understanding virus–host interactions, particularly the mechanisms of cell entry, is critical for developing effective therapeutics and vaccines. Current approaches often rely on live virus assays requiring high-containment facilities, limiting speed, scalability, and accessibility. As a proof-of-principle, we developed a novel screening platform—Ceudovitox—using pseudotyped viruses (PVs) bearing the chikungunya virus (CHIKV) envelope protein. These PVs were engineered to express herpes simplex virus-1 thymidine kinase, enabling selective killing of infected cells with ganciclovir. A heterogeneous CRISPR-Cas9 knockout cell pool was then screened using this "killer" PV system, allowing identification of CHIKV entry factors via next-generation sequencing. Overall design: Pooled CRISPR screen using pseudotype infection, in duplicate