Immunogenicity and cross reactivity in the efferent arm of the immune response. Groups of C57-A2Kb transgenic mice (n = 3) were vaccinated with 3 × 106 syngenic DCs pulsed with p30, mp30 or mp540 (10 μg/ml), and PADRE (5 μg/ml). Ten days after immunization, the mice were sacrificed and the pooled splenocytes (from 3 mice) were pulsed with the peptide used for immunization (100 μg/ml) and expanded in vitro for 5 days, on day 5, the splenocytes were tested in ELISPOT wells for IFN-γ production after exposure to EL4-A2Kb cells pulsed with wildtype peptide, modified peptide and Mock (control), respectively, *P < 0.001 (t test)