Fig. 2

Peripheral tumor-reactive T cells persist at the time of progression. a Expression-level of targeted tumor antigens in pre-treatment (unfilled bars) and resistant (filled bars) tumor samples determined by genome expression microarray (NA-17 not represented on the gene array). Gene expression of targeted antigen transcripts are normalized to median signal intensity of all genes on the array and expressed as expression units. b IFN-γ ELISpot assessing the T cell reactivity against the four peptides used in the vaccine, gp100, Melan-A, MAGE-3, NA-17, over time during initial treatment. PBMCs isolated at each time point and stimulated with the indicated melanoma peptides or media control. Samples analyzed in triplicate and presented as the mean number of spots per number of PBMCs with standard deviation. Mean number of spots for each peptide compared to media control. P-values for gp100, Melan-A, MAGE-3, and NA17 peptide versus media control listed from top to bottom, respectively, at each time point, *p < 0.05, **p < 0.001, ***p < 000.1 (c) IFN-γ ELISpot showing persistent T cell reactivity against three melanoma peptides (gp100, Melan-A and MAGE-3) at the time of progression. PBMCs stimulated with media control, EBV antigen (control peptide), gp100, Melan-A, MAGE-3, and NA17 peptide. Samples analyzed in triplicate and presented as the mean number of spots per number of PBMCs with standard deviation. Mean number of spots compared to media control. *p < 0.05, **p < 0.001, ***p < 000.1