Transduction catalysis: Doxorubicin amplifies rAAV-mediated gene expression in the cortex of higher-order vertebrates

Rapid and efficient gene transduction via recombinant adeno-associated viruses (rAAVs) is highly desirable across many basic and clinical research domains. Here, we report that vector co-infusion with doxorubicin, a clinical anti-cancer drug, markedly enhanced rAAV-mediated transgene expression in the cerebral cortex across mammalian species (cat, mouse, and macaque), acting throughout the time period examined and detectable at just three days after transfection. This enhancement showed serotype generality, being common to all rAAV serotypes tested (2, 8, 9, and PHP.eB) and was observed both locally and at remote locations consistent with doxorubicin undergoing retrograde axonal transport. All these effects were observed at doses matching human blood plasma levels in clinical therapy and lacked detectable cytotoxicity as assessed by cell morphology, activity, apoptosis, and behavioral testing. Altogether, this study identifies an effective means to improve the capability and scope of in vivo rAAV applications, amplifying cell transduction at doxorubicin concentrations paralleling medical practice.