Capsid-incorporated antigens elicit a varied immune response. (A-D) C57BL/6J mice were immunized with 1010VP of Ad vectors. Post-immunization sera were collected after 50 days post-injection for ELISA binding assays. 20 μM of synthetic peptide 33RGD-His6(RGD residue flanked by His6/Linker) was bound to the plate. The plates were then incubated with immunized mice sera, the binding was detected with isotype-specific HRP-conjugated anti-mouse secondary antibody (A, IgG; B, IgG1; C, IgG2b; D, IgG2c). OD absorbance represents the sera levels of antibodies. Values are expressed as the mean ± standard error of three replicates. Control viruses are Ad5, Ad/HVR2-His6 and Ad/HVR5-His6.