CHARACTERIZATION OF RETROVIRUS-INDUCED SC-1 CELL-FUSION

Virus-mediated cell-cell fusion with Moloney MLV and SC-1 cells was ch aracterized. The level of fusion was highly dependent on the cell line used for propagation of the virus. Efficient fusion appeared to be ve ry sensitive to negative charges on the cell surface and surroundings. Addition of polycations, removal of serum, and treatment with neurami nidase or hyaluronidase all stimulated fusion. Conversely, fusion was inhibited by fibronectin. Kinetic results and the time of action of in hibitors indicated that virus particles (or virus material) on the cel l surface lead directly to fusion. The fusion then proceeded rapidly a nd required actin movement as shown by cytochalasin inhibition.