TABLE 2.
Virus titers of ecotropic gammaretroviruses on untreated mouse cells and cells transfected with the mCAT-1 receptor or treated with the glycosylation inhibitor tunicamycin
| Expt and cellsa | Log10 virus titerb
|
||
|---|---|---|---|
| AKV MLV | MoMLV | FBLV | |
| Expt 1 | |||
| NIH 3T3 | 4.7 | 5.1 | 5.8 |
| M. dunni | 4.3 | 2.3 | 5.0 |
| M. minutoides | <0 | 3.5 | 3.2 |
| Expt 2 | |||
| NIH 3T3 | 4.1 | 5.2 | ND |
| M. dunni | 4.4 | 1.5 | ND |
| M. dunni (mCAT-1) | 5.4 | 4.7 | ND |
| M. minutoides | <0 | 3.8 | ND |
| M. minutoides (mCAT-1) | <0 | 4.9 | ND |
| Expt 3 | |||
| NIH 3T3 | 5.1 | 5.8 | ND |
| NIH 3T3 + Tu | 5.2 | 5.2 | ND |
| M. dunni | 5.0 | 2.7 | ND |
| M. dunni + Tu | 4.9 | 4.0 | ND |
| M. minutoides | <0 | 3.2 | ND |
| M. minutoides + Tu | <0 | 3.8 | ND |
a
Cells stably transfected with mCAT-1 are indicated. Tunicamycin (Tu) was used at 0.2 μg/ml.
b
Virus titers were determined by the XC overlay test, in which the indicated cells were infected with virus dilutions, irradiated 4 days later, and overlaid with XC cells to identify clusters of virus-infected cells (37). Titers represent the number of XC PFU in 0.2 ml in representative experiments. Infections were done four times for the first experiment, three times for the second, and three times for the third. ND, not done.