AAV with ALB(1.9) promoter driven SEAP

This AAV expresses SEAP driven by a liver ALB(1.9) promoter.

The ALB(1.9) is a synthetic promoter of ~1.9 Kb. It is based on the human Albumin promoter as well as several other regulatory elements. This synthetic promoter gives an extremely high level of long-term, liver-specific transgene expression that is 100-100 fold greater than that of the CMV promoter. For short-term (1-2 weeks post-injection into mouse liver), ALB(1.9) gives comparable expression relative to that of the CMV promoter. However, the expression level of the CMV promoter decreases 100-1000 fold from its peak level within 10-20 weeks of DNA administration whereas the ALB(1.9) promoter sustains its initial high level of expression for over 1 year. Compared to the regular ALB promoter, which is also commonly used for liver-specific transgene expression, the expression level from ALB(1.9) is about 10-100 fold greater.

The SEAP reporter gene encodes a truncated form of the human placental alkaline phosphatase that lacks the membrane anchoring domain. Therefore, the protein can be efficiently secreted from transfected cells allowing for detection of reporter gene activity without cell lysis. Using a secreted reporter protein has several advantages over traditional reporter assays: 1) Cell lysis is not required for analysis so a single set of cells can be used for both the SEAP assay and another purpose; 2) Gene expression kinetics can be studied by the repeated collection of the culture medium from the same cultures; and 3) By changing the culture medium prior to an experiment, the assay background is reduced to an extremely low level.