Adeno-associated virus type 2 vectors: transduction and long-term expression in cerebellar Purkinje cells in vivo is mediated by the fibroblast growth factor receptor 1 : bFGFR-1 mediates AAV2 transduction of Purkinje cells

Abstract

The receptor for adeno-associated virus serotype 2 (AAV2) in Purkinje cells has not been identified, but based on work carried out in non-neuronal cell lines, heparan sulfate proteoglycan is thought to act as a primary receptor, with basic fibroblast growth factor receptor-1 being reported as a co-receptor. In this study, using antibody interference and protein competition strategies, we show specific reduction in Purkinje cell transduction by AAV2 vector in the presence of these inhibitors. We also demonstrate AAV2-mediated transgene expression in Purkinje cells in vivo that extends out to one year post-injection. These results provide new information on fibroblast growth factor receptor-1 involvement in AAV2-mediated transduction of Purkinje cells and have important implications for AAV-mediated treatment of various cerebellar disorders.

Fig. 1

Schematic of AAV vector vTR-UF11. pA, polyadenylation signal; Neo, neomycin phosphotransferase coding sequence under transcriptional regulation of the thymidine kinase (TK) promoter, GFP coding sequence under transcriptional regulation of the hybrid CMV enhancer and β-actin promoter. Arrows indicate transcriptional start sites. TR, black boxes

Fig. 2

Role of the bFGF receptor in AAV transduction of cerebellar Purkinje cells. Arrows indicate the presence or absence of GFP-positive cells at the site of injection. Animals were injected with AAV vector vTR-UF11 after preinjection with: a Anti-bFGFR antibody; b Anti-bFGR antibody plus bFGFR blocking peptide; c Anti-bFGFR antibody; d Anti-tyrosine hydroxylase antibody; e bFGF protein; f PBS treatment

Fig. 3

Persistence of gene expression in mouse Purkinje cells 1 year post-injection. Sagittal sections of mouse cerebellum in animals injected with 2.7 × 10⁸ functional units of vTRUF11. a GFP expression in Purkinje cells 1 week post-injection, 4× magnification, scale bar 300 microns. b Transduction in Purkinje cells 1 year after injection, 10× magnification