Infection of NIH 3T3 and NRK 52E cells expressing feline leukemia virus-C cell surface receptor (FLVCR)
| Target Cell . | Titer (ffu/mL) . | |||
|---|---|---|---|---|
| Amphotropic MuLV . | FeLV-A . | FeLV-B . | FeLV-C . | |
| FEA | 2.6 × 105 | 1.4 × 107 | 1.8 × 104 | 2.4 × 105 |
| GP104C1 | 2.0 × 105 | 1 | 0 | 9.2 × 106 |
| NIH 3T3 | 2.9 × 105 | 0 | 0 | 0 |
| NIH 3T3(FLVCR) | 3.4 × 105 | 0 | 3 | 47 |
| NRK 52E | 6.8 × 105 | <10 | 65 | <10 |
| NRK 52E(vector) | 7.2 × 105 | <10 | 48 | <10 |
| NRK 52E(FLVCR) | 4.8 × 105 | <10 | <102 | 1.4 × 105 |
| Target Cell . | Titer (ffu/mL) . | |||
|---|---|---|---|---|
| Amphotropic MuLV . | FeLV-A . | FeLV-B . | FeLV-C . | |
| FEA | 2.6 × 105 | 1.4 × 107 | 1.8 × 104 | 2.4 × 105 |
| GP104C1 | 2.0 × 105 | 1 | 0 | 9.2 × 106 |
| NIH 3T3 | 2.9 × 105 | 0 | 0 | 0 |
| NIH 3T3(FLVCR) | 3.4 × 105 | 0 | 3 | 47 |
| NRK 52E | 6.8 × 105 | <10 | 65 | <10 |
| NRK 52E(vector) | 7.2 × 105 | <10 | 48 | <10 |
| NRK 52E(FLVCR) | 4.8 × 105 | <10 | <102 | 1.4 × 105 |
FEA = feline embryonic fibroblasts; FeLV = feline leukemia virus; ffu = focus-forming unit; MuLV = murine leukemia virus. Titers were determined by alkaline phosphatase staining, which was performed 72 hours after exposure to LAPSN pseudotyped with amphotropic MuLV, FeLV-A, FeLV-B, or FeLV-C envelope proteins. Titers were averaged from three plates, from two infection studies. NIH 3T3(FLVCR) and NRK 52E(FLVCR) are cells that were transduced with MSCV(1.8 kb)neo then selected (×10d) in G418. NRK 52E(vector) are control cells that were transduced with MSCVneo then selected (×10d) in G418. The species of origin of FEA, GP104C1, NIH 3T3, and NRK 52E cells are cat, guinea pig, mouse, and rat, respectively.