Abstract
The purpose of this paper is to describe the immunocytochemical localization of envelope G protein of vesicular stomatitis virus in the cells throughout the infectious cycle, in comparison with pure morphological observation. Vero cells, MDBK cells and Swiss 3T3 cells were examined at various times after infection. They were fixed with PLP fixative and treated with 0.05% Triton X before incubation with mouse monoclonal antibody and rabbit antimouse IgG coupled to rhodamine. The G protein was seen around nuclear membranes at 2.5hr and on Golgi areas at 3hr. At 4-6hr, it was detected not only on Golgi areas but also on cell surfaces. For electron microscopic immunostaining, Vero cells were fixed first in the mixture of glutaraldehyde and paraformaldehyde and then with PLP fixative followed by 0.05% saponin treatment. They were immunostained with the monoclonal antibody and rabbit anti-mouse IgG coupled to peroxidase. The G protein could be identified in the luminar sides of Golgi membranes and smooth vesicles. For pure morphological observation, Vero cells were fixed in glutaraldehyde and paraformaldehyde and routinely embedded in Epon. At 5-6hr, Golgi apparatus became larger than normal in uninfected cells and contained fuzzy materials in the luminar sides of Golgi membranes and smooth vesicles that corresponded to the immunostained reaction products. It is concluded that smooth vesicles are possible candidates for the transportation of G protein, instead of clathrin coated vesicles.
