Figure 3.
VP22-EGFP fusion protein transport from COS-7 cells infected with HIV–lentiviral vectors to adherent cells. (Left) EGFP-positive cells after coplating of target cells with COS-7 cells previously infected with the HIV-VP22-EGFP/HSA vector. (Right) EGFP-positive cells after coplating of target cells with COS-7 cells previously infected with the HIV-EGFP/HSA vector. Antibody staining for simian virus 40 T-antigen (Anti-T) was tested on the same slides. (A) Brain choroid plexus cells. (B) Human endothelial cells. (C) HeLa cells. VP22-EGFP was found not only in the nucleus (n), but also in the cytoplasm (c) in endothelial cells and in HeLa cells. Approximately 3 × 104 COS-7 cells and 3 × 105 recipient cells were mixed and plated onto cover slips in 12-well plates in 2.2 ml of medium and processed for antibody staining and microscopy 3 d later. (Scale bar, 15 μm.)