Abstract
Gene transfer to the central nervous system provides powerful methodology for the study of gene function and gene-environment interactions in vivo, in addition to a vehicle for the delivery of therapeutic transgenes for gene therapy. The aim of the present study was to determine patterns of tropism exhibited by pseudotyped lentiviral vectors in the rat substantia nigra, in order to evaluate their utility for gene transfer in experimental models of Parkinson's disease. Isogenic lentiviral vector particles encoding a GFP reporter were pseudotyped with envelope glycoproteins derived from vesicular stomatitis virus (VSV), Mokola virus (MV), lymphocytic choriomeningitis virus (LCMV), or Moloney murine leukemia virus (MuLV). Adult male Lewis rats received unilateral stereotactic infusions of vector into the substantia nigra; three weeks later, patterns of viral transduction were determined by immunohistological detection of GFP. Different pseudotypes gave rise to transgene expression in restricted and distinct cellular populations. VSV and MV pseudotypes transduced midbrain neurons, including a subset of nigral dopaminergic neurons. In contrast, LCMV- and MuLV-pseudotyped lentivirus produced transgene expression exclusively in astrocytes; the restricted transduction of astroglial cells was not explained by the cellular distribution of receptors previously shown to mediate entry of LCMV or MuLV. These data suggest that pseudotyped lentiviral vectors will be useful for experimental gene transfer to the rat substantia nigra. In particular, the availability of neuronal and astrocytic-targeting vectors will allow dissociation of cell autonomous and cell non-autonomous functions of key gene products in vivo.