TABLE 2.
In vitro interaction of gag-pol RNA particles, fusion-defective pseudotyped virus, and amphotropic virus with VSV-Ga
| Virus | Neor titer (CFU/ml) on:
|
|
|---|---|---|
| 208F cells | BHK cells | |
| LZRNL (G) | 1.0 × 106 | 8.0 × 105 |
| LZRNL (gag-pol RNA) | ||
| Alone | <1 | <1 |
| + VSV-G | 4.2 × 104 | 3.4 × 104 |
| LZRNL (G-P127R) | ||
| Alone | 1.8 × 102 | 2.0 × 102 |
| + VSV-G | 8.0 × 105 | 6.0 × 105 |
| LZRNL (A) | ||
| Alone | 6.0 × 105 | <1 |
| + VSV-G | 8.0 × 105 | 4.4 × 105 |
Preparations of VSV-G pseudotyped virus LZRNL (G) were made by conventional methods (37). Conditioned medium of 293GP/LZRNL containing LZRNL (gag-pol RNA), 293GP/LZRNL/G-P127R containing LZRNL (G-P127R), and 293GP/LZRNL/amphotropic containing LZRNL (A) were harvested and used to infect 208F and BHK cells before and after exposure to wild-type VSV-G. For the in vitro assembly of infectious particles, 0.5 ml of each of these conditioned media was mixed with 0.5 ml of conditioned medium of 293 cells transfected with the pCMV-G and centrifuged at 14,000 rpm in Beckman F2402 rotor at 4°C for 1 h. Pellets were resuspended with PBS and used to infect 208F and BHK cells. Titers of the viruses treated in vitro with VSV-G represent total infectious virus recovered from 1 ml of corresponding conditioned medium.