OBJECTIVERecombinant adeno-associated virus type 8 (rAAV8) mediating transgene expression in mice was investigated using co-expressed report gene of secreted Gaussia princeps luciferase (Gluc) and non-secreted firefly luciferase(Fluc).

METHODSrAAV8-Gluc/Fluc was prepared and infected HEK293 cells to test its performance in vitro. BALB/c mice were received rAAV8-Gluc/Fluc at different doses by intravenous injection (iv) or intramuscular injection (im). Then Glue activities in blood were measured,the whole-body images for Flue activities were performed and Flue activities of tissue lysate were also detected.

RESULTSrAAV8-Gluc/Fluc was successfully prepared and could infected HEK293 cells. The Glue was mainly detected in the culture media while the Flue was mainly detected within cells. The blood Glue activities of mice received rAAV8-Gluc/Fluc by iv or im peaked at 10-20 d post injection and persisted for at least 120d. The blood Gluc activities increased at the rAAV8-Gluc/Fluc dose-dependent manner. For mice received rAAV8 by iv, Fluc mainly expressed in liver and minor Fluc expression was also found in cardiac muscle and skeletal muscle. For mice received rAAV8-Gluc/Fluc by im, Fluc mainly expressed in local skeletal muscle and secondly in liver.

CONCLUSIONrAAV8-Gluc/Fluc has been prepared successfully and its mediating transgene expression in mice has been investigated. This research will facilitate preclinical studies for rAAV8-mediated gene therapy.