FIG. 1.

Establishment of cell lines containing a stably integrated Tax-responsive 18x21-EGFP reporter cassette. (A) HOS and HeLa cell lines were transduced with the SMPU-18x21-EGFP lentivirus vector at an MOI of approximately 2. Infected cells were then cloned in 96-well plates by using limiting dilutions. Individual clones were expanded and screened for stable integration of the reporter cassette by infection with the Ad-Tax adenovirus vector. The reporter-containing clones usually ranged from 60 to 80%. Cloned HeLa/18x21-EGFP and HOS/18x21-EGFP cells infected with a control adenovirus vector, Ad-tTa, are shown for comparison. (B) HeLa/18x21-EGFP cells seeded on a coverslip were transduced with LV-Tax for 48 h. Immunofluorescence of Tax was carried out as described in Materials and Methods. DAPI, 4′,6′-diamidino-2-phenylindole.