Differential response to alanine screened altered variants of SYIPSAEKI when conjugated to PSNPs or pulsed with DCs. The 6–8 week old BALB/c mice were immunized once with PBS alone, DCs alone (1 × 106 DCs per mouse), KI conjugated to PSNPs (PSNPs-KI, 25 µg per mouse KI and 1% solids PSNPs), ex vivo KI pulsed DCs (DCs/KI, DCs pulsed with 5 µg/mL KI and 1 × 106 cells immunized per mouse), or ex vivo KI pulsed DCs coinjected with mixed in PSNPs (DCs/KI/PSNPs, 1 × 106 cells injected with 0.67% PSNPs). Five weeks after the last immunization, splenocytes from immunized mice were harvested and restimulated with alanine altered peptides in an in vitro ELISpot assay for IFN-γ. Data shown as mean +/- SD of SFU/million cells per assay triplicates (pooled cells from four mice per group). * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001.