FIG. 1.

Tax-coding DNA induced CD4⁺ or CD8⁺ CTL lines specific to Tax. Splenic T cells were isolated from nu/+ rats inoculated with a Tax expression vector and periodically stimulated with formalin-fixed FPM1-V1AX cells. After 3 months of stimulation, three CTL lines (4O1, 4O2, and 4J3) were established. (A) These cells were labeled with fluorescein isothiocyanate-conjugated anti-rat CD4 and PE-conjugated anti-rat CD8 for 30 min. After being washed, these cells were subjected to flow-cytometric analysis. (B) FPM1-V1AX (▪), G14-Tax (▨), or G14 (□) cells were labeled with ⁵¹Cr for 1 h and used as target cells. CTL lines were used as effectors at an E/T cell ratio of 10. Results are expressed as mean percent lysis ± the standard deviation of triplicate wells. Similar results were obtained in four independent experiments.