Figure 5.

Generation of primary CTL from naive CD8⁺ 2C cells cultured with QL9 peptide presented by Drosophila cell APC. (a) CTL activity of CD8⁺ 2C cells stimulated with L^d.B7, L^d.B7.ICAM, or L^d.ICAM APC plus QL9 peptide (10 μM) in the absence of exogenous cytokines. (b Left) CTL activity of CD8⁺ 2C cells stimulated with L^d.B7 APC plus QL9 peptide (10 μM) in the absence or presence of anti-IL-2 and/or anti-IL-4 mAb (2 μg/ml). (b Right) CTL activity of CD8⁺ 2C cells stimulated with L^d.ICAM APC plus QL9 peptide (10 μM) in the absence or presence of recombinant IL-2 (20 unit/ml). (c) CTL activity of CD8⁺ 2C cells stimulated with L^d.B7 APC plus QL9 peptide in the absence or presence of either anti-IL-2 or anti-IL-4 mAb (20 μg/ml). Purified CD8⁺ 2C cells (5 × 10⁵) were cultured with 2 × 10⁶ Drosophila APC. After 4 days, the cells were harvested and CTL activity was tested against [⁵¹Cr]-labeled RMA-S.L^d target cells loaded with p2Ca or control P1A.35-43 peptide (32); P1A peptide binds strongly to L^d but has no detectable affinity for the 2C TCR (32). The data show the mean level of specific ⁵¹Cr release from duplicate cultures.