The initial objective of the project was to create a large number of viral pseudotypes that express the RBPs of various animal viruses and evaluate their capacity to infect human cells. To this end, over 100 RBP genes from 14 viral families have been synthesized, used for producing pseudotypes and tested in more than 50 different human cell lines, resulting in >5000 RBP-cell combinations. A machine learning model has been developed to predict which viruses may enter human cells, and host factors involved in viral entry have been identified. The focus of this research has been on enveloped RNA viruses, which demonstrate the greatest potential for emergence and are more frequently amenable to pseudotyping. Subsequently, experimental evolution has been employed to examine the potential for RBPs to enhance their infectivity in human cells. A variety of methodologies have been investigated for this purpose, with a particular focus on coronavirus spike proteins. The experiments have identified specific mutations that increase RBP efficiency, contingent on factors such as cell type, receptor availability, entry route, and temperature. To further advance our comprehension of viral entry determinants, a systematic analysis of documented virus receptors has been conducted, and cellular proteins with a heightened propensity for serving as virus receptors have been identified. A novel coronavirus receptor has been identified and characterised, and the tools required for the discovery of new receptors are being implemented. Finally, laboratory techniques for the development of entry inhibitors, such as phage display, are the subject of ongoing work.
