Levels of cFIX expression and anti-cFIX IgG antibody after transduction of 129 × C57BL/6 hemophilia B mice.
(A) Levels of cFIX in mice transduced as neonates. Neonatal 129 × C57BL/6 hemophilia B mice were injected intravenously with a single dose of 1 × 1010 TU/kg hAAT-cFIX–WPRE at 2 or 3 days after birth. The average plasma cFIX antigen levels ± SEM is shown for the indicated number of animals (N). (B) Levels of cFIX in mice transduced as adults without preceding HGF. Adult (6-week-old) 129 × C57BL/6 hemophilia B mice were injected intravenously with a single dose of 3.3 × 109 TU/kg hAAT-cFIX–WPRE, and plasma cFIX antigen levels were determined. Values for individual mice are shown. (C) Anti-cFIX IgG antibody levels in mice transduced as neonates. Plasma from the mice whose cFIX levels are shown in panel A was tested for anti-cFIX–specific antibodies at the indicated times after transduction as detailed in “Materials and methods.” Individual values are shown for the 2 mice that developed a transient and low-titer antibody. Fifteen mice did not develop detectable antibodies at any time point, which is indicated as a single line at the bottom of the graph. (D) Anti-cFIX IgG antibodies in mice transduced as adults without preceding HGF. Plasma from the mice whose cFIX levels are shown in panel B was tested for anti-cFIX–specific antibodies. Individual animals have the same symbol in both panels.
