Respiratory Syncytial Virus (RSV) is a major cause of severe lower respiratory tract infections and a major cause of mortality in children under 5 years old and the elderly worldwide. While RSV impose a huge disease burden on public healthcare system, the development of specific antivirals is impeded by a lack of knowledge of virus multiplications mechanisms, virus-host interactions or pathogenicity. Here, we propose to comprehensively map RSV host interactions and characterize the cellular response to infection through an integrated multi-omics approach and using experimental systems close to natural infection. By using state-of the- art-of proteomics and transcriptomics, we characterize the protein-protein interactome, analyze the proteome of cells expressing the individual viral proteins (effectome), and assess the influence of RSV infection on cellular mRNA expression, protein abundance, and phosphorylation. We systematically map the identified viral-induced perturbations onto a network of known cellular protein-protein interactions and signalling pathways. This comprehensive network will highlight RSV-induced perturbations and pinpoint RSV host dependency-factors, whose functional importance and therapeutic potential will be assessed by conducting genetic and drug-based loss and gain of function experiments. Biochemical and structural methods, and further analyses of the cellular response in genetically or drug-perturbed cells will yield insights into the molecular function of selected proteins. The proposed multilevel approach will thus reveal yet unstudied proteins and pathways determining RSV growth, pathology or viral host defense mechanisms, which will shed light on unresolved questions of RSV biology, and reveal hotspots amenable to therapeutic intervention.
