Immunoelectron microscopy of Rift Valley fever viral morphogenesis in primary rat hepatocytes

The morphogenesis of the hepatotropic phlebovirus Rift Valley fever virus (RVFV) has been examined by immuno-electron microscopy in primary hepatocyte cultures derived from genetically susceptible and resistant rat strains. RVFV replicates in both cell types with growth kinetics comparable with those seen in other permissive cells. However, in contrast to that has been observed in other cell types, RVFV replication in hepatocytes is associated with maturation at cellular surface membranes in addition to the smooth internal membranes of the Golgi and endoplasmic reticulum. Envelope acquisition at surface membranes occurred primarily on basolateral membranes. The events occurring in RVFV morphogenesis were indistinguishable in hepatocytes from resistant and susceptible animals; however, hepatocytes from susceptible animals produced significantly higher titers of virus.