Figure 3.

(A) ES12-specific cytolytic activity of CTL line 4–1 from donor NPH54 in a 5 hr ⁵¹Cr release cytotoxicity assay. Peptide-specific lysis titrated downwards with diminishing effector-to-target cell ratio, and nonspecific lysis of unpulsed targets was less than 5%. Target cells were heterologous HLA-B52-matched BCL (homozygous typing line, Akiba: HLA-A24; HLA-B52, as in Fig. 2A), prepulsed with 10 μM ES12. (B) ES12-specific cytolytic activity of a CTL line from donor NPH97 in a 5 hr ⁵¹Cr release cytotoxicity assay. The CTL line was generated by restimulation of 14-day STCLs (cultured as described in Materials and Methods) with ES12-pulsed, washed, irradiated autologous BCL. Peptide-specific lysis titrated downwards with each 3-fold diminution in effector-to-target cell ratio, and nonspecific lysis of unpulsed targets was less than 5%. Target cells were heterologous HLA-B52-matched BCL (Akiba) as in Fig. 2A, prepulsed with 10 μM ES12. (C) Lysis of HLA-B52-matched heterologous targets (Akiba BCL) expressing endogenously processed ESAT-6. Targets were infected with rVV-ESAT-6 and rVV-control as in Fig. 2B and were labeled with ⁵¹Cr the following day. CTL line 4–1 raised against ES12 specifically lysed the rVV-ESAT-6-infected targets; lysis of rVV-control-infected targets was below 10%.