Figure 5.

Internalization of bound viral particles. 3T3/CD33 cells were used as the target cells. After incubating target cells at 4°C with viral particles for 2 hr, cells were washed with PBS and incubated in D10 medium for 1 hr at 37°C, followed by washing three times with PBS and then incubation in trypsin/EDTA for 10 min at 37°C. Lysates of cells were analyzed by immunoprecipitation with anti-SU and anti-p30 antiserums. Lanes: 1, 33K67; 2, 33E67; 3, mock transfection (with pHIT60 and pCnB plasmids, but no envelope protein plasmids).