Maturation site of dengue type 2 virus in cultured mosquito C6/36 cells and Vero cells.

The maturation of dengue virus (type 2, New Guinea B strain; abbreviated Den-2) in cultured mosquito C3/36 cells and Vero cells was studied by immunoelectron microscopy for the first 7 days after cells were infected, assays of the virus were done by the peroxidase-antiperoxidase method. Virus titers in both kinds of cells were highest on day 6. These cells were then observed with an electron microscope. Den-2 was round and measured about 50 nm in diameter. The virus matured mainly at the membranes of cytoplasmic vacuoles and vesicles, but a few budding viral particles were seen in the cell surface membrane. Immunogold labelling with rabbit antiserum against the E protein of Japanese encephalitis virus was used to locate specific antigens of the Den-2 envelope protein. The results showed that the E protein was in vacuoles, vesicles, and endoplasmic reticulum of the cells. In this study there were no differences between C6/36 cells and Vero cells infected with Den-2.