Adeno-associated viruses (AAVs) belong to the Paraviridae family and are being developed as potential vectors for human gene therapy. In the Early Edition of the Proceedings of the National Academy of Sciences, Guang-Ping Gao and colleagues report the isolation of novel non-human primate AAVs (Proc Natl Acad Sci USA 2002, DOI:10.1073/pnas.182412299).

They aligned known primate and non-primate AAV genome sequences and selected conserved regions for amplification by PCR. This allowed them to isolate two new viruses, AAV7 and AAV8, from the DNA of rhesus monkey heart tissues. Gao et al. then produced AAV vectors packaged with AAV7 and AAV8 capsid proteins and tested the chimeric virions; the non-human AAV reacted poorly with antibodies against human AAV serotypes. Furthermore, when they looked at in vivo performance they found that the new viruses were very efficient gene-delivery vectors for mouse skeletal muscle and liver.

The low immunogenicity and favorable...