Cell Fusion by the Antigen-antibody Complex of Sendai Virus Studied by Electron Microscopy

Summary Cell fusion of Ehrlich ascites tumour cells caused by antigen-antibody complexes of Sendai virus was studied by electron microscopy. The fusion process was similar to that produced by virus. The fusion of envelopes of virus particles aggregated by antibodies and cell membranes was not observed under the conditions employed, though cell fusion was enhanced. This finding supported the hypothesis that the formation of cell-cell bridges but not of cell-envelope-cell bridges is involved in the initiation of cell fusion.