Table I. PTB is critical for CD40L expression in both resting and activated CD4+ T cells.
| Virus | MFI (CD40L) | % Δ in MFI (Uninfected to infected in same population)a | |
|---|---|---|---|
| Uninfected | Infected | ||
| shCTRL | |||
| Non-Activated | 33.9+/- 0.10 | 35.32+/-1.2 | 4.2% |
| Activated | 245.7+/-40.3 | 260.6+/-29.1 | 6.1% |
| shPTB | |||
| Non-Activated | 43.1+/-4.3 | 39.33+/-3.06 | -8.7% |
| Activated | 271.3+/-24.9 | 204.5+/-17.1 | -24.6% |
|
| |||
| w/cycloheximide | |||
|
| |||
| shCTRL | |||
| Non-Activated | 38.95+/-0.15 | 40.0+/-0.22 | +2.7% |
| Activated | 46.4+/-0.4 | 52.1+/-0.7 | +12.3% |
| shPTB | |||
| Non-Activated | 38.3+/-0.15 | 36.1+/-1.3 | -5.7% |
| Activated | 46.9+/-1.65 | 38.4+/-1.3 | -18.1% |
a
Primary CD4+ T cells were infected either pLVTHM-shCTRL or pLVTHM-shPTB virus in the presence of IL-2 and PHA. 10 days later cells were either untreated (top rows) or treated with cycloheximide for 30 min (bottom rows). Cells were then left unactivated for 2 h or activated with PMA/ion for 2 h (top rows) or 30 min (bottom rows) and analyzed for GFP (infected) and CD40L (activated) expression. The MFI are the average of 3 (top) and 2 (bottom) independent experiments and the numbers in the right column represent the percent change in the average MFI between the uninfected and infected subpopulations in the same culture.