Convection-enhanced delivery of AAV-2 combined with heparin increases TK gene transfer in the rat brain

Adeno-associated virus type2 (AAV-2) binds to heparan-sulfate proteoglycans on the cell surface. In vivo, attachment of viral particles to cells adjacent to the injection tract limits the distribution of AAV-2 when infused into the CNS parenchyma and heparin co-infusion might decrease the binding of AAV-2 particles to cells in the vicinity of the infusion tract. We have previously shown that heparin co-infusion combined with convection enhanced delivery enhances distribution of the GDNF family trophic factors (heparin-binding proteins) in the rat brain. In this work we show that heparin co-infusion significantly increases the volume of distribution of AAV-2 as demonstrated by immunoreactivity to the transgene product 6 days after infusion into the rat striatum.