Fig 2. Diverse MUC1 Antigen Preparations Generate Specific Immune Responses in Tolerant MUC1.Tg and Non-Tolerant WT Mice.

MUC1.Tg mice were given three immunizations with vaccines containing 9mers, 22mers or rotating tumor lysates (Fig 1). Lymph node-derived T-cells were culture expanded for 7–14 days with DCs pulsed with the immunizing antigens. Antigen-specific T-cells were enumerated for intracellular IFN-γ production when re-stimulated with DCs pulsed with short peptides (A) and long peptides (B). Data are shown after subtracting background from unpulsed DCs to facilitate visual comparisons. See Fig 2D for examples of representative unsubtracted backgrounds. A representative of 2 experiments is shown; pools of 7 mice were used. (C) Wide specificity of the lysate-sensitized T-cells: Lysate sensitized T-cells from MUC1.Tg mice or WT mice showed specificity against 19 out of 19 MUC1 peptides from both TR and non-TR regions. (D) MUC1.Tg mice were immunized twice with vaccines containing either long peptides from TR, APG 22mer (APGSTAPPAHGVTSAPDTRPAP) or the CT peptide (SLSYTNPAVAATSANL). After in vitro stimulation with DCs pulsed with immunizing peptides, antigen specific T-cells were analyzed for intracellular IFN-γ against dendritic cells pulsed with peptides (APG 22mer or CT) or no peptide (UP). One representative of three experiments is shown; pools of 7 mice were used in each experiment.