Ultrastructural aspects of the dengue virus (flavivirus) particle morphogenesis.

The pathway of dengue virus infection in both mosquito and Vero cells in culture has been described. However, a number of stages associated with dengue virus morphogenesis remain unclear. For this reason further study involving electron microscopic in situ hybridisation of viral RNA and immunolocalisation of envelope proteins was carried out. The data obtained support the hypothesis that both viral RNA and viral proteins assemble when anchored to the viral-induced smooth membrane structures which occur within the lumen of the rER. Following the formation of the nucleocapsid, virus particles acquire their envelopes inside the lumen of the rER and associated structures. Some virus particles only are transferred to the Golgi system for maturation and are delivered from the cell by exocytosis. Nevertheless, the majority of virus particles do not pass the Golgi system but instead remain enclosed in rER-derived vesicles, even after cell and syncytial lysis. The virus replication pathway is a cell line independent process.