Figure 5. Cell surface-expressed A2/K^b activates CTL in the absence of cognate antigen.

A. 2.5×10⁴ Mel13, 003 or ILA1 CTL were incubated for 12 hours at 37°C with 10⁵ C1R cells stably transfected to express equal levels of either A2 or A2/K^b at the cell surface. Supernatant was subsequently assayed for MIP-1β content by ELISA. The mean ± SD of two replicate assays is shown. B. 2.5×10⁴ Mel13 CTL were incubated for 12 hours at 37°C with 10⁵ C1R cells stably transfected to express either A2 or A2/K^b at the cell surfaceSupernatant was assayed for IFNγ and TNFα content by cytokine bead array. C. CD107a expression by ILA1 and Mel13 CTL following a 12 hour incubation at 37°C with C1R cells stably transfected to express either A2 or A2/K^b on the cell surface. For (A-C), C1R cells were not previously pulsed with peptide.