Figure 5
HER2 immunization primes strong neu-specific CD4+ T-cell responses in mice. (A) C57BL/6 mice were primed with DEC-HER2 in combination with poly IC. Two weeks after the boost, splenocytes were re-stimulated with medium alone, HIV gag peptides, HER2 peptide pool 5, or corresponding neu peptide pool 4 (2 μg/mL). IFNγ production was measured by intracellular cytokine staining. (B) Functional avidity of HER2/neu-specific CD4+ T cells. Titrated doses of HER2 or neu peptide pool were used to re-stimulate splenocytes, and IFNγ production was quantified. Data depict the percentage of maximum response at each concentration. ***P < 0.001. Results of two experiments are shown, and six mice were in each group. EC50, concentration of peptide that leads to 50% of the maximal responses; HER, human epidermal growth factor receptor; IFNγ, interferon-gamma; poly IC, polyinosinic/polycytidylic acid.