Identification of small molecules capable of enhancing viral membrane fusion.

Several approaches have been developed to analyze the entry of highly pathogenic viruses. In this study, we report the implementation of a Bimolecular Multicellular Complementation (BiMuC) assay to safely and efficiently monitor SARS-CoV-2 S-mediated membrane fusion without the need for microscopy-based equipment. Using BiMuC, we screened a library of approved drugs and identified compounds that enhance S protein-mediated cell-cell membrane fusion. Among them, ethynylestradiol promotes the growth of SARS-CoV-2 and Influenza A virus in vitro. Our findings demonstrate the potential of BiMuC for identifying small molecules that modulate the life cycle of enveloped viruses, including SARS-CoV-2.