FIG. 2.

RRV/FIV transduces the liver more efficiently than VSV-G/FIV with reduced cytotoxicity. Mice were intravenously injected via the tail vein with a single bolus of control lactose buffer (A), 10 × 10⁷ TU of RRV/FIV vector (B), or 35 × 10⁷ TU of VSV-G/FIV vector (C). At 24 h postinjection, the mice were bled, and the blood samples were collected and assayed for SGOT and SGPT (four mice per treatment group). At 3 weeks postinjection, the mice were sacrificed and the liver was stained with X-Gal and examined under stereo microscopy (A to C). (D) Summary of β-galactosidase expression levels in mice receiving two different doses of RRV-pseudotyped FIV vector (3 × 10⁷ TU/mouse, n = 5; 10 × 10⁷ TU/mouse, n = 7). (E) Summary of β-galactosidase expression levels in mice receiving three different doses of VSV-G-pseudotyped FIV vector (7.2 × 10⁷ TU/mouse, n = 3; 35 × 10⁷ TU/mouse, n = 8; 68 × 10⁷ TU/mouse, n = 3). (F) SGOT (left) and SGPT (right) levels from recipient mice on day 1 postinjection. The levels of SGOT and SGPT from the recipient mice of RRV/FIV vector were not different from those of buffer control recipients and were within the normal range. In contrast, the mice receiving the VSV-G/FIV vector had significantly higher levels of SGOT and SGPT than both control mice and RRV/FIV recipient mice on day 1 postinjection (✽, P < 0.05 [two-tailed Student t test]). On day 7, the levels of SGOT and SGPT in these mice returned to normal range. The results of one of three representative experiments is shown, with a total of ≥12 mice per treatment group.