Fig. 2. The effect of human albumin on AAV8 transduction.

a. Transduction enhancement is related to direct interaction of AAV with serum. AAV8/luc viruses were incubated with human serum or PBS at 1:100 dilution for 2 hr at 4°C, then the mixture was used to transduce Huh7 cells either in medium with FBS, serum free medium, or serum free medium plus human serum just before addition of AAV8 pre-incubated with PBS. 24 hr later, fold increase of transgene expression was calculated. b. AAV8 interaction with human albumin. 1×10¹⁰ particles of AAV8/luc were incubated with human sera or PBS for 2hr at 4 °C, then the mixture of virus and human serum or PBS was applied to pre-Ig bound column. After washing, the column binding proteins were eluted for AAV8 genome copy number analysis. c. AAV8 transduction with albumin depleted serum. 1×10⁸ particles of AAV8/luc were incubated with human serum or albumin depleted serum at different dilutions or PBS for 2hr at 4°C. Then the mixture was used to infect Huh7 cells in serum free medium. Two days later, luciferase was detected from the cell lysate, and the fold increase of transgene expression was calculated while compared to PBS. d. Recombinant human albumin enhances AAV8 transduction. AAV8/luc was incubated with recombinant human albumin (50mg/ml) or human serum at different dilutions or PBS. Transgene expression was detected 48hr later, and the fold increase of transgene expression was calculated when compared to PBS.