hFIX expression in immunocompetent animals.

Expression of hFIX (left-hand panels) and the development of anti-hFIX antibody (right-hand panels) was examined in 6- to 8-week-old male C57/BL/6 (A,B), 4-week-old male BalBC (C,D), and 10-week-old male Fv129 (E,F) mice following administration of 5 × 1010particles of rAAV CAGG-FIX. Cohorts of C57BL/6 mice received vector through the portal vein (closed square, n = 4), tail vein (inverted triangles, n = 4), or into the muscle (diamonds, n = 6). BalBC mice received the same vector dose through the tail vein (inverted triangles, n = 4) or into the muscle (diamonds, n = 4). Fv129 mice received vector through the portal vein (squares, n = 4) or into the muscle (diamonds, n = 4). Mice were bled at the indicated number of weeks following vector administration and assayed for hFIX or the presence of anti-hFIX using an ELISA. Note that the units depicting anti-hFIX antibody levels are an estimate, as they are derived from dilutions of a monoclonal antibody. The results are represented as means with standard errors.