Table 1.
MACS1 Envs Use Both CCR5 and CXCR4 to Mediate Fusiona
| Envelope | CCR5 | CXCR4 |
|---|---|---|
| ADA | ++++ | − |
| 89.6 | +++ | ++++ |
| HXB2 | − | ++++ |
| MACS1br6b-81 | ++ | ++ |
| MACS1br6b-91 | ++ | ++ |
| MACS1br6b-3 | +++ | +++ |
| MACS1br6b-132 | ++++ | +++ |
| MACS1br6a-9 | ++++ | +++ |
| MACS1sp7b-11 | +++ | ++++ |
| MACS1sp8a-2 | +++ | ++++ |
| MACS1sp7a-142 | − | − |
| MACS1sp7a-13 | +++ | ++++ |
| MACS1sp7b-9 | +++ | ++++ |
a
293T cells cotransfected with pCR3.1Env and pLTR-Tat were mixed with Cf2-Luc cells cotransfected with pcDNA3-CD4 and either pcDNA3-CCR5 or pcDNA3-CXCR4. Cells were harvested following an 8-h incubation. The levels of fusion in cells expressing CD4 and CCR5 or CXCR4 as measured by luciferase activity are indicated as follows: −, +, ++, +++, and ++++ representing levels that were at background, 1–25%, 25–50%, 50–75%, and 75–100% of control Envs, respectively. Unless otherwise indicated, results are representative of five independent assays. 1Results from one fusion assay. 2Results from two fusion assays.