Feline caliciviruses (FCV) are common pathogens of cats and are increasingly being recognized as a cause of severe virulent systemic (VS-FCV) disease. Compared to other strains of FCV, VS- FCV strains infect a broader range of cell types. The interaction between a virus and specific molecules on the cell surface often determines the types of cells that can be infected; the correct complement of ‘receptor’ molecules is necessary for a virus to infect a particular cell type. Two cellular receptors have been identified for FCV – feline junctional adhesion molecule A (fJAM-A) and sialic acid, a sugar molecule. These researchers are investigating the link between FCV receptor interactions and strain virulence. The goal of this project is to determine the capacity of VS-FCV and non-VS-FCV strains to bind specific sugar molecules on the cell surface and to identify the role this plays in FCV infection of different cell types. In the longer term, the findings will facilitate understanding of the mechanisms by which FCV cause disease.