Basic Fibroblast Growth Factor Enhances Transduction, Distribution, and Axonal Transport of Adeno-Associated Virus Type 2 Vector in Rat Brain

Abstract

The ubiquitous expression of cell surface heparan sulfate proteoglycan, a binding receptor for adeno-associated virus type 2 (AAV-2), may account for the broad host range of this vector. Because the fibroblast growth factor receptor type 1 has been postulated to be a coreceptor for successful AAV-2 entry into host cells, we designed a strategy to investigate whether coadministration of this virus with basic fibroblast growth factor (bFGF) can enhance AAV-2-mediated gene delivery. We injected AAV-2-thymidine kinase (AAV-2-TK) vector into rat striata and checked whether coinjection with bFGF enhanced transduction and/or enlarged the area of transgene expression. Immunostaining confirmed the tropism of AAV-2-TK for neurons. The previous injection (7 days before vector delivery) of bFGF had no major impact on vector distribution area. However, when the vector was coinjected with bFGF, the right striatum showed an average viral transduction volume of 5 mm(3), which was more than 4-fold larger when compared with the left side (AAV-2-TK plus phosphate-buffered saline). This result clearly indicates that simultaneous injection of bFGF with AAV-2-TK can greatly enhance the volume of transduced tissue, probably by way of a competitive block of AAV-2-binding sites within the striatum. Robust TK immunoreactivity was also observed in the globus pallidus, which receives anterograde projections from the striatum. We propose that postsynaptic transport of recombinant particles was likely responsible for the distribution of TK in the globus pallidus on both bFGF-treated and untreated sides. In summary, we found that bFGF acts as an adjuvant for distribution of AAV-2 in rat brain.

Efficient gene therapy-based method for the delivery of therapeutics to primate cortex

“…Monitored delivery has allowed us to quantify and control aberrant events, such as cannula reflux and leakage of infusate into ventricles (18). Anterograde (19) and retrograde (20) transport along axonal tracts is a consistently observed phenomenon in CED of AAV vectors. This remarkably efficacious process suggests that axonal transport might be able to mediate effective distribution to the primate cortex from the relatively compact thalamus, because axonal projections from the thalamus distribute widely to lamina III and IV of the cerebral cortex.…”

Novel Caprine Adeno-Associated Virus (AAV) Capsid (AAV-Go.1) Is Closely Related to the Primate AAV-5 and Has Unique Tropism and Neutralization Properties

“…The potential utility of AAV-2 vectors for treating serious human diseases including hemophilia A and B (8), Parkinson's disease (1,19,31), heart failure (9, 21), and cystic fibrosis (14), among others, has been established in animal models. However, the presence of human preexisting antibodies reactive with primate AAV serotypes may reduce the clinical usefulness of vectors made from these serotypes (17).…”

Transduction of non-human primate brain with adeno-associated virus serotype 1: vector trafficking and immune response

“…The pressurized infusate then engages the perivascular space and distribution is significantly aided by the pulsation of blood vessels. We have shown previously that pulse pressure appears to be the main driver of CED (Hadaczek et al, 2004). As a result, the vector is distributed evenly, and at higher concentrations over a larger area, than in the absence of CED, that is, by diffusion alone.…”

“…Finally, differential distribution of cellular AAV receptors, such as heparan sulfate proteoglycan (HSPG) for AAV2 (Summerford and Samulski, 1998) and a-2,3 and a-2,6 N-linked sialic acids for AAV1 (Wu et al, 2006b), can both affect vector trafficking and cellular specificity. Various coinfusates, such as heparin and basic fibroblast growth factor (bFGF), can be used to block the binding temporarily, thereby allowing AAV2 particles to spread further into the brain parenchyma (Nguyen et al, 2001;Mastakov et al, 2002;Hadaczek et al, 2004), although similar techniques have not been reported for AAV1.…”