ELISPOT analysis of FSP-specific T cells. T cells (1 x 10⁴ cells/well) were stimulated with 3.5 x 10⁴ T2 cells pulsed either with the FSP or the control peptide P68 as targets. The number of IFN-gamma-releasing activated T cells (spots) for the total number of cells analyzed (10⁴) is given. Reactivity against P68 is shown as a measure of background IFN-gamma release.