Fig 6. Ad–αGal immunocomplexation following i.p. homologous prime/boost immunization did not increase anti-Gal-directed humoral response in anti-Gal mice by day 42.

αGal epitope-directed IgG humoral responses (anti-Gal serum IgG titers) were analyzed at 42 d after priming, corresponding to 28 days after the third i.p. vector dose of 1E+10 physical vector particles. (a) Pre-immunization anti-Gal IgG titers as established by 3–4 αGal pre-immunizations with PKM extract were quantified the day before immunization with Ad or Ad–αGal vectors. (b) Post-immunization anti-Gal IgG titers were determined at 28 days after the last i.p. vector immunization. ‘n’ indicates the number of animals per group. ‘Empty’ is unmodified control vector Ad Empty which does not carry an expression cassette. All other vectors carried CMV-promoter driven iOVA expression cassettes. ‘Ad’ is unmodified control vector Ad iOVA, while the other vectors were αGal-decorated at the indicated capsomer site in hexon HVR1 or HVR5, fiber or penton. P values were calculated by unpaired, two-tailed t-test assuming equal variances. Only P values <0.05 are indicated.