Scaleable chromatographic purification process for recombinant adeno-associated virus (rAAV)

Abstract

Background: Adeno-associated virus (AAV) is a human parvovirus currently being developed as a vector for gene therapy applications. Traditionally AAV has been purified from cell lysates using CsCl gradients; this approach however is not likely to be useful in large-scale manufacturing. Moreover gradient-purified AAV vectors tend to be contaminated with significant levels of cellular and adenoviral proteins and nucleic acid. To address the issue of purification we have developed a process scale method for the rapid and efficient purification of recombinant AAV (rAAV) from crude cellular lysates.

Methods: The preferred method for the purification of rAAVbetagal includes treatment of virally infected cell lysates with both trypsin and nuclease followed by ion exchange chromatography using ceramic hydroxyapatite and DEAE-Sepharose in combination with cellufine sulphate affinity chromatography.

Results: Purification of rAAV particles from crude cellular lysates co-infected with adenovirus was achieved using column chromatography exclusively. Column-purified rAAV was shown to be greater than 90% pure, free of any detectable contaminating adenovirus, biologically active, and capable of directing efficient gene transfer to the lungs of both cotton rats and mice.

Conclusions: This study demonstrates the feasibility of using column chromatography alone for the isolation of highly purified rAAV vector. The methods described here are advancements in procedures to purify rAAV and are adaptable for commercial production of clinical-grade rAAV vector.