Scanning and freeze-fracture electron microscopy of rabies virus infection in murine neuroblastoma cells.

A persistent infection of CVS strain of rabies virus was established in murine neuroblastoma cells, C-1300, by a serial passage of the cells infected with a low input multiplicity. Little cytopathic effects were seen in the infected cultures and the cell growth was not interfered, although 90-100% of the cells were bearing intracytoplasmic inclusions and the infectious virus was constantly recovered from the supernatant. Scanning electron microscopy disclosed preferential budding of the virus from fine cellular processes with a relative sparing of the cell body. Freeze-fracture of the infected cells revealed that the intracytoplasmic inclusion (matrix) was composed of an aggregate of fine particles with a diameter of approximately 200 A. Intramembrane particles were distributed sparsely and randomly in the viral envelope.