TABLE 1.
CD81 dependency of E2 binding to various cell types
| Cell line | Derivation | Binding (median FI)
|
||||
|---|---|---|---|---|---|---|
| MAba
|
E2661 gp in the presence ofb:
|
|||||
| Anti-CD81 5A6 | Irrelevant isotype control | No addition | GST-EC2 | Anti-CD81 5A6 | ||
| KM3 | Rat melanoma | 4.5 | 4.4 | 4.8 | NT | NT |
| KM3-CD81 | Rat melanoma | 661.2 | 8.3 | 162.3 | 6.3 | 5.3 |
| HepG2 | Human liver | 12.4 | 13.7 | 12.9 | 11.6 | 13.4 |
| Huh7 | Human liver | 56.6 | 6.5 | 125.9 | 6.5 | 5.1 |
| PLC/PR5 | Human liver | 63.2 | 5.9 | 110.5 | 7.3 | 4.8 |
| Daudi | Human B cell | 191.1 | 6.1 | 122.9 | 8.4 | 6.4 |
| Molt-4 | Human T cell | 250.3 | 2.4 | 66.4 | 5.9 | 6.8 |
a
CD81 expression was measured with MAb 5A6 (10 μg/ml), and background FI was measured with an irrelevant anti-gp120 isotype-matched control MAb.
b
E2661 at a concentration (1 μg/ml) shown not to saturate cell-expressed CD81 was incubated with GST-EC2 (50 μg/ml) for 1 h and subsequently tested for binding the various cell types. In addition, cells were incubated with 5A6 (10 μg/ml) for 1 h before being tested for the ability to bind E2661. Cell-bound E2 antigen was visualized with MAb 11/4b and anti-rat IgGPE. NT, not tested.