Absence of humoral response against β-gal in the in utero–transduced sheep at 42 months posttransduction.

(A) Kinetics of the antibody response in control (▪) (nos. 7119, 7122, and 7124) and experimental (▵) (nos. 698, 703, and 704) sheep. Each value represents the mean ± SD. Each sample was assayed in triplicate. Significant levels of anti–β-gal antibodies were produced in the control sheep following boosting, while the antibody responses in the in utero–transduced sheep were almost undetectable. The concentration of anti–β-gal antibodies present within the serum samples was quantitated by constructing a standard curve with mouse anti–β-gal antibody. (B) Kinetics of the antibody response to chicken egg albumin in control (nos. 7119, 7122, and 7124) and experimental (nos. 698, 703, and 704) sheep. Each value represents the mean ± SD for all 6 sheep (3 control and 3 experimental). Each sample was assayed in triplicate. Significant levels of antichicken egg albumin antibodies were produced in all sheep following boosting. The concentration of antichicken egg albumin antibodies present within the serum samples was quantitated by constructing a standard curve with mouse antichicken egg albumin antibody.