Replication of dengue viruses in mosquito cell cultures--a model from ultrastructural observations.

Mosquito cell cultures infected with human sera from dengue-1 and dengue-2 outbreaks, started in Rio de Janerio by 1986 and 1990 respectively, were examined by electron microscopy at different times post the infection of cell cultures. More information was obtained about cell penetration of virus particles in the presence or not of antibodies, their pathway inside the cells, replication mode and exist. Infectiveness of the virus at those different stages can only be attributed to the particles appearing inside the trans-Golgi vesicles; most of all newly formed virus particles remain inside the RER-derived cell vesicles or inside lysosomes, even during cell lysis. Groups of larger particles, 65-75 nm in diameter at dengue-2 infections, persist during cell passage. The large amounts of smooth membrane structures, as vesicles or tubules inside the RER, are attributed to a cell response to viral infection.