%0 Journal Article %A Dourmashkin, R. R. %A Tyrrell, D. A. J. %T Electron Microscopic Observations on the Entry of Influenza Virus into Susceptible Cells %D 1974 %J Journal of General Virology, %V 24 %N 1 %P 129-141 %@ 1465-2099 %R https://doi.org/10.1099/0022-1317-24-1-129 %I Microbiology Society, %X SUMMARY Influenza A2 virus particles were observed attached to the surface of chick CAM after 1 h at 4 °C. After incubation at 35 °C, virus particles were seen inside cytoplasmic vesicles (viropexis). Subsequently, the virus particles penetrated the vacuolar membranes and uncoating was observed within the cytoplasm without the intervention of lysosomal enzyme. Fusion of virus coat with cell membrane was not thought to play a part in virus entry. The pinocytosis of virus was shown to be an active process, triggered by the attachment of virus to the cell membrane. Viropexis occurred in cells treated with amantadine, cytochalasin B and colchicine and in normal cells to which heated virus had been added. Virus was seen eluting after treatment with antihaemagglutinin antibody, but after treatment with antineuraminidase antibody, the virus did not elute; in neither case did the virus enter the cells in the presence of antibody. %U https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-24-1-129