The hidden impact of producer cells on virion composition and infectivity

The cells infected by a virus in vivo are critical determinants of infection and disease. These same susceptible cells can also provide a wide range of options for viral propagation. The type of cell used to produce a virus, i.e. the producer cell type, can change the macromolecular composition of viruses and other factors associated with viral inoculum independent of genetic selection. Changes in the post-translational modifications of viral proteins, virion protein and lipid composition, and the types of viral structures released from different producer cells have been observed for several virus families. These producer cell-dependent changes can have wide ranging consequences on subsequent infection by altering viral tropism, antigenicity, and overall infectious capacity. The changes imparted by the producer cell impact experimental outcomes and influence viral spread and disease in vivo. In this review, we discuss the literature documenting the effects that producer cell type has on the macromolecular composition and infectious properties of virions and viral inoculum. We discuss the evidence of producer cell-dependent changes on the outcome of infection and antigenicity from diverse viral families. These observations highlight the need to better understand the impact producer cell type has on viral infections and disease.